TASIT TEKNOLOJISI_PASIF

Transkript

MARMARA ÜNİVERSİTESİ
TEKNOLOJİ FAKÜLTESİ
TAŞIT TEKNOLOJİSİ
PASİF EMNİYET
Yrd. Doç. Dr. Abdullah DEMİR
Source World Health Organization
ALV-General Presentation 2014 v.1.1 – 3; ALV General 2014
Complete Safety System Supplier
ALV-General Presentation 2014 v.1.1 – 3; ALV General 2014
Knowledge saves lives
Bruno DiGennaro, Volvo & Child Passenger Safety, April 23, 2009
Safety Strategy
“Cars are driven by people. The guiding principle behind everything
we make at Volvo, therefore, is – and must remain – safety.”
Assar Gabrielsson and Gustaf Larson, founders of Volvo
Volvo Cars Gent; PR & Communicatie; mdemey; Issue date: Update 01/2011, Security Class: Public
Drive Towards Zero
Vision: To develop cars that don’t crash.
Zero killed or badly injured in a Volvo car 2020
Johan Konnberg - Volvo Car Electrification Strategy, 2012-10-23
Toyota
Toyota
Toyota
5 phases of safety
4. Damage reduction
•3-point Safety Belt
•Deformation zones
•PRS
•SIPS
•WHIPS
•ROPS
•IC
1. Normal driving
•DSTC and CTC
•RSC
•Collision Warning
•Emergency Brake
Assist
•Lane Departure
Warning
•Ready Alert Brake
2. Conflict
•Driver Alert Control
•Adaptive Cruise
Control
•IDIS
•BLIS
•Active Bending
Lights
•Distance Alert
3. Avoidance
•Pedestrian Detection
5. After
with Full Auto Brake
collision
•Collision Warning
with Full Auto Brake
•City Safety
1. Normal driving
2. Conflict
3. Avoidance
4. Damage reduction
5. After collision
Okuma Metni:
Dinamik Denge ve Çekiş Kontrolü (DSTC)
Sistem, aracın ne yönde gittiği, lastiklerin ne kadar hızlı döndüğü ve ne kadar
direksiyon hareketi uygulandığı gibi faktörleri hesaba katmaktadır. DSTC tüm bu
bilgileri kullanarak, potansiyel bir savrulmayı algılayabiliyor ve bunu önlemek
için devreye girerek motor gücünü azaltır ve/veya uygun tekerlekleri frenler.
Motor Sürükleme Kontrolünü (EDC) kullanarak, motor freni sırasında
tekerleklerin kilitlenmesini de önler. Savrulmayı önlemek için DSTC sisteminin
daha da erken ve daha hassas bir biçimde çalışmasına yardım etmek amacıyla
Gelişmiş Denge Kontrolü (ASC) sistemi çok eksenli yeni bir sensöre sahiptir.
Ancak ASC'nin işi size tatmin edici bir sürüş deneyimi de sunmak; böylece viraj
alırken aracın dinamik açıdan çok daha dengeli olduğunu hissedebiliyorsunuz.
Bir başka özellik de Viraj Çekiş Kontrolü (CTC). Bu sistem, viraj alırken içteki
çekiş tekerleği yol tutuşunu kaybetmeye başladığında bu tekerleği frenleyip, gücü
bu tekerlek yerine dıştaki tekerleğe aktararak çalışır. Bazı araçlarda performanslı
şekilde otomobil kullanmak istendiğinde, DSTC bir Spor Ayara da sahiptir. Bu
ayar, motor gücü azaltma fonksiyonunu devre dışı bırakır ve sürücünün
direksiyon simidi ve gaz pedalını dinamik bir şekilde kullandığını ve fazla ileri
gitmediğini algıladığı (belli bir sınırı aşarsa o zaman normal DSTC fonksiyonuna
geri dönüyor) sürece arka tekerleğin kontrollü bir miktarda kaymasına izin verir.
Volvo
Boyun Zedelenmesi Koruma Sistemi (WHIPS - Whiplash Protection
System): Bir anlık dikkatsizlikle bir sürücünün öndeki araca çarpması. Sonuç
da, kafanın aniden geriye doğru atılmasıyla oluşan kırbaç etkisine bağlı uzun
dönemde rahatsızlık veren bir yaralanma olabilir. Uzun süreli yaralanma riskini
%50'ye varan oranda azaltmaya yardım edecek bir sistem geliştirmiştir. Arkadan
bir darbe durumunda, WHIPS sistemi yolcu ya da sürücünün koltuk arkalığının
tamamını hareket ettirirken, koltuk başlığı, bir topu nazikçe yakalar gibi sabit
kalarak boynu desteklemektedir.
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Volvo
Dinamik Denge ve Çekiş Kontrolü (DSTC)
Viraj Çekiş Kontrolü (CTC)
Motor Sürükleme Kontrolü (EDC)
BLIS (Blind Spot Information System)
IDIS (Intelligent Driver Information System)
Roll Over Protection System (ROPS)
Roll Stability Control (RSC)
Structural Insulated Panel (SIP)
LDW (Lane Departure Warning)
Holistic approach to safety
Mitigation:
Azaltma
SAFETY
Emniyet “tehlike bulunmaması hali” olarak
tanımlanmaktadır. Ancak taşıt trafiğinde mutlak
bir emniyetten söz edilemez. Emniyet kavramı
tehlike oranı yada diğer bir deyişle rizikoyu
tamamlayıcı bir emniyet derecesi ile ifade
edilebilir.
Riziko ise kaza olma olasılığı ve kaza sonucu
olabilecek zarar miktarı ile belirlenebilir.
Emniyetlilik, kaza olasılığı ile mümkün olan
zarar oranının çarpımının az olmasıdır.
Active safety: Prevention of accidents
Passive safety: Reduction of accident consequences
Safety in traffic.
Terms and influencing factors
• Active safety
• Driving safety
ACTIVE SAFETY
Driving safety is the result of a harmonious chassis and suspension design
with regard to wheel suspension, springing, steering and braking, and is
reflected in optimum dynamic vehicle behavior.
Conditional safety results from keeping the physiological stress that the
vehicle occupants are subjected to by vibration, noise, and climatic conditions
down to as low a level as possible. It is a significant factor in reducing the
possibility of misactions in traffic.
Vibrations within a frequency range of 1 to 25 Hz (stuttering, shaking, etc.)
induced by wheels and drive components reach the occupants of the vehicle
via the body, seats and steering wheel. The effect of these vibrations is more
or less pronounced, depending upon their direction, amplitude and duration.
Noises as acoustical disturbances in and around the vehicle can come from
internal sources (engine, transmission, propshafts, axles) or external
sources (tire/road noises, wind noises), and are transmitted through the
air or the vehicle body.
ACTIVE SAFETY
Noise reduction measures are concerned on the one hand with the development of
quiet-running components and the insulation of noise sources (e.g., engine
encapsulation), and on the other hand with noise damping by means of insulating
or anti-noise materials.
Climatic conditions inside the vehicle are primarily influenced by air temperature,
air humidity, rate of air flow through the passenger compartment and air pressure.
Perceptibility safety
Measures which increase perceptibility safety are concentrated on
• Lighting equipment (Lighting),
• Acoustic warning devices (Acoustic signaling devices),
• Direct and indirect view (Driver's view: The angle of obscuration caused by the
A-pillars for both of the driver's eyes – binocular – must not be more than 6
degrees).
Operating safety
Low driver stress, and thus a high degree of driving safety, requires optimum design
of the driver's surroundings with regard to ease of operation of the vehicle controls.
Binocular: İki gözün de kullanılmasını gerektiren
Reading Text:
Biomechanical Criteria/Approach
Several years later it became apparent that this approach is incomplete since it is not
linked with the human tolerance limits as a consequence of trauma due to accidents.
Thus the need became evident to evaluate the safety of a car with biomechanical
criteria requiring the need to verify, in case of accident, that the stress suffered by the
occupants are lower than human tolerance limit. This became known as the so-called
biomechanical approach. The logical scheme to define the safety standards
according to this approach is multi-disciplinary.
Fig.: Schematic representation of the biomechanical approach.
L. Morello et al.: The Automotive Body, Vol. 2: Structural Design,Springer Science + Business Media B.V. 2011
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Pasif emniyet, bir kaza ile
karşılaşılması
durumunda,
kazanın olumsuz sonuçlarını
olabildiğince azaltmak amacıyla
yapılan bütün yapısal ve tasarım
özelliklerini kapsamaktadır.
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Kapı içi çelik bar sistemleri
Enerji sönümleyen direksiyon
sistemleri
Hava yastığı sistemleri
Emniyet kemer sistemleri
Ayarlanabilir fren pedal sistemi
Baş destekleme veya aktif
boyunluk sistemi
Çocuk koruma sistemi
Aktif diz destekleme sistemi
Elektronik kapı kilitleme ve
mandallama sistemleri
Kaza sonrası yangın önleme
sistemi
Kaza sonrası acil bilgi sistemi
Kaza sonrası kolay çıkış sistemi
Kaza sonrası acil aydınlatma
sistemi
Kaza sonrası elektrik sisteminin
kesilmesi
Kaza sonrası yakıt sisteminin
kesilmesi
PASSIVE SAFETY
Risk to pedestrians in event of collisions with
passenger cars as a function of impact frequency and
seriousness of injury (based on 246 collisions)
PASSIVE SAFETY
Exterior safety: The term "exterior safety" covers all vehicle-related measures which
are designed to minimize the severity of injury to pedestrians and bicycle and
motorcycle riders struck by the vehicle in an accident. Those factors which determine
exterior safety are:
• Vehicle-body deformation behavior,
• Exterior vehicle-body shape.
The primary objective is to design the vehicle such that its exterior design minimizes
the consequences of a primary collision (a collision involving persons outside the
vehicle and the vehicle itself).
The most severe injuries are sustained by passengers who are hit by the front of the
vehicle, whereby the course of the accident greatly depends upon body size. The
consequences of collisions involving two-wheeled vehicles and passenger cars can only
be slightly ameliorated by passenger-car design due to the two-wheeled vehicle's often
considerable inherent energy component, its high seat position and the wide
dispersion of contact points. Those design features which can be incorporated into the
passenger car are, for example:
• Movable front lamps,
• Recessed windshields wipers,
• Recessed drip rails,
Recessed: Gönme, girintili
Ameliorated: İyileştirmek, düzeltmek
• Recessed door handles.
PASSIVE SAFETY
Interior safety
The term "interior safety" covers vehicle measures whose purpose is
to minimize the accelerations and forces acting on the vehicle
occupants in the event of an accident, to provide sufficient survival
space, and to ensure the operability of those vehicle components
critical to the removal of passengers from the vehicle after the
accident has occurred.
The determining factors for passenger safety are:
• Deformation behavior (vehicle body),
• Passenger-compartment strength, size of the survival space during
and after impact,
• Restraint systems,
• Impact areas (vehicle interior), (FMVSS 201),
• Steering system,
• Occupant extrication,
• Fire protection.
PASSIVE SAFETY
Laws which regulate interior safety (frontal impact)
are:
• Protection of vehicle occupants in the event of an
accident, in particular restraint systems (FMVSS 208,
ECE R94, injury criteria),
• Windshield mounting (FMVSS 212),
• Penetration of the windshield by vehicle body
components (FMVSS 219),
• Parcel-shelf and compartment lids (FMVSS 201).
Rating-Tests:
• New-Car Assessment Program (NCAP, USA, Europe,
Japan, Australia),
• IIHS (USA, insurance test),
• ADAC, ams, AUTO-BILD.
Distribution of accidents by type of collision,
symbolized by test methods yielding equal results
An example crash test requirement profile
Bernd Heißing | Metin Ersoy (Eds.), Chassis Handbook Fundamentals, Driving Dynamics, Components, Mechatronics, Perspectives, 2011
Şasi ve Karoseri Sistemleri ve Darbe Emici Sistemler:
Baş yaralanma kriterinin (HIC - Head Injury Criterion) belirlenmesinde baş
ivme değerleri kullanılmaktadır. Göğüs yaralanma kriteri; göğüs kafesinin
müsaade edilebilir maksimum ivmesi ile sınırlandırılmıştır.
Diğer genel şartlar şunlardır:
• Çarpma sırasında kapılar açılmamalıdır,
• Çarpmadan sonra kapılar yeterince açılabilmelidir,
• Ön camın koruduğu bölgeye taşıt parçaları girmemelidir,
• Direksiyon simidinin yatay kayma miktarı < 10 cm olmalıdır,
• Yolcu mahallindeki kapaklar açılmamalıdır,
• Hayati hacim boyutları küçülmemelidir.
Bu şartların tamamlayıcısı olarak, darbe durumunda enerji absorbe edebilme
özelliği bulunan ön yapı, belirli ve olabildiğince düzgün bir yavaşlama ivmesine
sebep olmalıdır. Yolcu bölümü ise, mümkün olabildiğince sağlam ve şekil
değişimine karşı dirençli olmalıdır. Eskinin ağır gövdeleri yerine, günümüzde
uzay kafes (SF-space frame) sistemine göre üretilmekte olan yüksek dayanımlı
profillerden yapılan hafif gövdeler ve çarpışma anındaki darbe kuvvetinin yolcu
kafesine ulaşmadan sönümlenmesi için eklenen ön deformasyon kuşakları
çarpışma anındaki kuvvetleri önemli ölçüde absorbe ederek hayat kurtarıcı bir
fonksiyon üstlenmektedir.
Darbe Emici Sistemler; gövde yapısı önden, arkadan ve yandan çarpmalardaki darbeyi
sönümleyecek şekilde yapılmıştır. Takviye saçları ve elemanları sayesinde kabin
deformasyonu minimumda tutularak yolcuların mükemmel korunması düşünülmüştür.
Ön/Arka Çarpışmalarda Darbe Sönümleyici Yapı; ön ve arka çarpışmalarda
mükemmel darbe sönümleme yapısı sayesinde kabini çevreleyen ön tampon takviyesi, alt
gövde elemanları birbirine mükemmel şekilde bağlanmıştır. Önden ve arkadan çarpışma
durumlarında alt gövde ve kabin şasisi darbe enerjisinin etkisini azaltmaya ve yaymaya
yardımcı olur. Bunun sonucu olarak kabin deformasyonu en aza indirgenir. Şasi kolları
üzerindeki çentikler sayesinde ön şasi kolları çarpışma enerjisini azaltmaya yardımcı olur.
Bunun sonucu olarak motor da ön çarpışmalarda nispeten korunmuş olur.
Yan Çarpışmalarda Darbe Emici Yapı; ön ve arka kapıların alt iç kısmına boru tipli
çelik barlar monte edilmiştir. Ön ve arka kapıların iç ve dış kısmına monte edilen takviye
saçları kapılara yandan gelen darbe enerjisini sönümler. Yan çarpışmalarda darbe enerjisi
direk takviye saçları, çelik barlar, taban traversi yoluyla yolcu kabinine yayılır. Bu
yayılmada bu elemanlar vasıtasıyla kabine direk giden enerji seviyesi minimumda tutulur.
Bunlara ilave olarak kabin güvenliği açısından gövdede maksimum korunmayı sağlamak
için yüksek mukavemetli çelik saçlar birbirine kaynatılmıştır. İlaveten baş bölgesi darbe
koruyucu yapıda yapılmıştır.
Kapı İçi Çelik Bar Sistemleri; her kapıda çelik bar sistemi bulunur ve yandan gelen
darbelerde karşı mukavemet sağladığı gibi çarpışma enerjisinin de gövde üzerinde
dağılımını sağlar. Ayrıca sürücü ve yolcuların üzerine gelebilecek olan hasarı minimize
eder.
Crumple Zones
What do crumple Zones help us to do?
Crumple Zones are structural area in the front and
sometimes the rear of the vehicle designed to absorb
energy upon an impact in a predictable way.
Ezilme Bölgeleri
Araçtaki ezilme bölgeleri kaza esnasında darbenin ortaya çıkardığı enerjiyi
emmek üzere sıkışacak şekilde tasarlanmış yapısal bir özelliktir. Ezilme
bölgeleri; önden çarpmalarda darbenin şiddetini azaltmak için genellikle
aracın önüne yerleştirilir, ancak aracın diğer parçaları üzerinde de
bulunabilir. Ezilme bölgeleri, araç tamamen duruncaya kadar geçen
süreyi uzatır. Kuvvetlerin ve yavaşlamanın büyüklüğü daha uzun bir
zamana yayıldığından yolcular bunu daha az hisseder. Dolayısıyla
emniyet kemeri doğru şekilde bağlı olan bir yolcunun bedenine ve
organlarına uygulanan kuvvet azalır ve çarpışma sonunda hayatta kalma
şansı artar.
Bir örnek verelim:
1500 kg ağırlığındaki bir araç, 40 km/h hızla bir duvara çarpıyor.
30 cm gövde deformasyonuna izin veren bir aracın darbe kuvveti yaklaşık
34,5 tondur. 50 cm deformasyona izin veren bir aracın darbe kuvveti yaklaşık
20 tondur.
Araç gövde sağlamlığı araç üreticileriş tarafından sürekli geliştirilir. Aracın
kabin ön duvarı, tavan köşesi ve C-sütunu gibi bazı bölgelerinde daha
dayanıklı malzemelerin kullanılması gövde sağlamlığını artırdığından
mükemmel çarpışma derecesi elde edilir.
Kia, Hava Yastığı, 2010
Ezilme Bölgeleri
SASİ VE GÖVDE EMNİYET
UYGULAMALARINA
ÖRNEKLER
Mercedes’ new GL-Class
Ensuring a large SUV protects its occupants and other road users presents a
significant challenge.
Crash Test Technology International, SEPTEMBER 2012
Çarpmalarda Şasi ve Karoserinin İşlevi
Kaynak: “Şase ve Karoseri” Sunumu, TÜVTURK, 08/03/2006.
Çarpmalarda Şasi ve Karoserinin İşlevi
Kaynak: “Şase ve Karoseri” Sunumu, TÜVTURK, 08/03/2006.
GÖVDE VE GÜVENLİK
Ön ve arka şasi kollarını birleştiren takviye barlar alüminyumdan yapılmıştır.
Taşıyıcı bar cıvata ile yüksek dayanımlı çelik (HSS) deformasyon elemanıyla
birlikte şasiye cıvata ile bağlanmıştır. Deformasyon elemanına çarpışma
kutusu adı verilir ve ön şasiye cıvatalıdır.
Opel Vectra, Gövde ve Güvenlik
Kaynak: Toyota
GÖVDE VE
GÜVENLİK
Kaynak: Toyota
Kaynak: Toyota
Pop-up Hood (Evolving GOA)
Kaynak: Toyota
Kaynak: Toyota
Kaynak: Toyota
EOS 2006
EOS 2006
EOS 2006
EOS 2006
Önden çarpışmada kuvvet akışı: Önden çarpışmada meydana gelen
kuvvetler üst ve alt şasi kolları üzerinden taban grubuna ve tavan sütunlarına
verilir.
2006 Passat
2006 Passat
EOS 2006
EOS 2006
EOS 2006
Audi Q7 Servis Eğitimi
READING TEXT
Reading text
Head acceleration values are used to determine the head injury criterion (HIC).
The comparison of measured values supplied by the dummies with the permissible
limit values as per FMVSS 208 (HIC: 1000, chest acceleration: 60 g/3 ms, upper leg
force: 10 kN) are only limited in their applicability to the human being.
The side impact, as the next most frequent type of accident, places a high risk of injury
on the vehicle occupants due to the limited energy absorbing capability of trim and
structural components, and the resulting high degree of vehicle interior deformation.
The risk of injury is largely influenced by the structural strength of the side of the
vehicle (pillar/door joints, top/bottom pillar points), load-carrying capacity of floor
cross-members and seats, as well as the design of inside door panels (FMVSS 214, ECE
R95, Euro-NCAP, US-SINCAP).
In the rear impact test, deformation of the vehicle interior must be minor at most. It
should still be possible to open the doors, the edge of the trunk lid should not
penetrate the rear window and enter the vehicle interior, and fuel-system integrity
must be preserved (FMVSS 301).
Roof structures are investigated by means of rollover tests and quasi-static car-roof
crush tests (FMVSS 216).
In addition, at least one manufacturer subjects his vehicles to the inverted vehicle drop
test in order to test the dimensional stability of the roof structure (survival space)
under extreme conditions (the vehicle falls from a height of 0.5 m onto the left front
corner of its roof).
Passenger compartment integrity
The compartment that houses the driver and passengers should remain intact after
an accident. Four measures are necessary:
• one is to incorporate crush zones at the each end of the car;
• the second is to stiffen the door and its immediate surroundings so that, in
the event of a side impact, it will not be penetrated or deflected violently
inwards and strike the occupants;
• third, the door trim must be soft or side air bags must be installed so that, if
the occupants are flung against it by the lateral acceleration, they will not be
seriously injured; and
• fourth, the door frame and not only its joins but also those between the pillars
and cant rail must be strong and stiff enough to react elastically to absorb the
shock loading.
Basically, the occupants must be housed in what amounts to a strong cage, which
will protect them also if the car rolls over. This generally entails the use of
substantial fillets, and perhaps the fitting of reinforcement plates, at the joints
between the pillars and the cant rails and sills. With the current need to reduce
overall weight, the use of thin gauge high strength ductile steel, instead of the
traditional thicker gauge high ductility material for structural members and some
body panels can help to improve both crushability and integrity of structures.
Automotive Engineering - Powertrain, Chassis System and Vehicle Body, Edited by David A. Crolla
PASSIVE SAFETY
It is important to design so that the loads due to an impact (whether front, rear or side) are,
so far as practicable, spread uniformly throughout the whole structure and that the
proportions of all the principal members of the cage containing the occupants are adequate
to react those loads elastically. Diagonal and transverse members may have to be
incorporated under the floor and, possibly, in the roof to transfer some of the loads from one
side to the other especially, although not solely, for catering for side or offset frontal impacts.
If the shock to the occupants is to be reduced significantly, a considerable proportion
of the total kinetic energy of the moving vehicle must be absorbed by the crush zone
as it collapses. At the front, the space between the grille and engine is inadequate for
absorbing that energy, except in very minor collisions. Consequently, in the more severe
accidents the engine will be pushed back, and it is important to prevent it from thrusting the
dash and toe board back until they strike the occupants and possibly trap them in their seats.
Consequently, the engine is generally mounted in a manner such that it will be deflected
downwards and slide under the toe board. In particular, if the engine is on a sub-frame, the
attachment of the longitudinal members of that frame to the toe board and front floor can
be designed to shear, to enable the whole installation to slide back under the floor. Even so,
the dash and toe board structure must still be stiff enough to prevent significant engine
intrusion into the saloon. At the rear, there is more space for a crush zone, but the fuel
tank must not be ruptured, which is the reason for the modern trend towards
installing fuel tanks much further forward than hitherto.
PASSIVE SAFETY
Ideally, the structure should collapse progressively at a constant rate, as if
it were a sprung buffer, Fig. A. One design method that has been
successful is to bow the longitudinal members so that they either spread
outwards or collapse progressively inwards when heavily loaded in
compression. Another is to incorporate vertical swaged grooves in the side
walls of straight members so that they collapse in a controlled fashion.
Ideally, the swages would be distributed alternately, along each side, over
the length of the longitudinal members of the frame or sub-frame.
However, the zig-zag, or concertina type of collapse thus aimed at is
extremely difficult to achieve in practice. Once the first kink has formed,
usually at the foremost swage, the member is already bowed and therefore
is more likely to continue to do so than to concertina. One manufacturer
has notched the corners of the rectangular section longitudinal members
to initiate progressive collapse. Each notch extends from the corner only a
very short distance down one face and a long distance across the other
face. However, one should be wary of introducing notches in such
structural members subject to fatigue loading, since cracks are liable to be
generated by and spread from the stress concentrations thus induced.
PASSIVE SAFETY
Fig. A: Diagrammatic representation of front longitudinal frame member
carrying the suspension and engine. The lengths of the swages, in each set of
four (in the top, bottom and two sides of the frame), become progressively
smaller, from the foremost to the rearmost, so that the frame will offer
progressively increasing resistance to collapse in a frontal impact. The lower
diagram shows it only partially collapsed.
PASSIVE SAFETY
It is preferable to encourage simple bowing by siting all the swages along either the
outer or the inner face rather than the top and bottom of each member, to cause
both to bow respectively either inwards or outwards. If both bow outwards, the
restriction imposed by the body panelling attached to them will help considerably
in providing a progressive reaction to the crushing force, If they bow inwards, they
are similarly restricted, but perhaps by the presence of the engine between them.
Inward bowing, however, tends to absorb more energy per unit of length of collapse.
This might or might not be what is desired, hence crash testing is essential for
proving designs.
An aspect that should not be overlooked is that swaging the sides of the
longitudinal members will reduce their stiffness for reacting to side loads. This
need not be serious if the ends of the vertical swages terminate short of the junction
with the top and bottom plates, each of which will then become, in effect, a
separate U-section member. The ends of the arms of each U terminate where the
swages begin, Fig. B. Incidentally, box section longitudinal members can be welded
fabrications. Alternatively, they could be square section tubes, the swages being
produced by hydroforming, using internal hydraulic pressure to expand the tube
into a mould.
PASSIVE SAFETY
Fig. B: Sections through two box section frame side members, one tubular and
the other fabricated. Although the swages in their sides weaken them so far as
taking side loads is concerned, these loads can be taken mainly in the sections
ABCD and EFGH. A useful rule of thumb is that a length equal to 16 multiplied
by the thickness of the metal represents the maximum length that is stable on
each side of each angle under compression, the measurement being taken from
the inner face in each corner or, for the fabricated section, the centres of the
bends.
The problem of the small car
In an impact with a large car, a small car is inevitably at a disadvantage because the inertia of the former
is greater than that of the small car. Moreover, the provision of a crush zone of adequate length at both
the front and back of the small vehicle is, of course, much more difficult. For this reason, the principle
of designing for the engine so that, when thrust backwards, it slides down beneath the toe board and
floor is the only practicable course. Furthermore, maximum use should be made of transverse
members to distribute the loads appropriately between all the longitudinal members, including the
body panelling, in a manner such that they are all equally stressed, as in Fig. C.
Fig. C: Plan view of a Toyota frame
designed to spread the loads
imposed by front and rear end
impacts uniformly throughout the
structure. The combination of the
front transverse member and the
diagonal members, A and B, one on
each side, triangulate the front end
of the frame to constrain it to
collapse concertina fashion, as
shown in Fig. A. Scrap view above:
elevation of a different frame,
showing how the loads are
distributed as viewed in a vertical
plane. The triangulation struts
shown in this example are fitted in
the door frames.
PASSIVE SAFETY
The problem of the small car (cont.)
An interesting feature in this illustration is the pair of gusset struts,
one each side, between the front transverse member and each
longitudinal side member. If an impact occurs as indicated by either of
the two thick arrows, the corner affected by the impact will be pushed
back. The gusset strut will stabilise the front end of the side member
so that, assuming it is designed to collapse concertina fashion, it will
not bow. Moreover, the transverse member will tend to pivot about the
opposite corner, which will be stiffened by the gusset strut. It therefore
will offer more resistance to the pivoting movement, and therefore a
larger share of the impact loading will be transferred to that side than
if there were no gusset member there. At the rear, the design is such
that the spare wheel will help to take some of the loading from a rear
end impact and transfer it to the main structure.
PASSIVE SAFETY
At the rear, the main requirement again is to utilise transverse members to the best
advantage. Also important is a robust C-pillar and a good supporting structure for
the rear axle. Double skinning the rear quarter panels can enormously strengthen
that part of the structure, although this does raise problems as regards repair to
minor damage. In general, the overall strength and integrity of the occupant cage
may need to be higher than that of a car with long crush zones front and rear.
Side impacts
As regards side impacts, there is not enough space within doors to serve as a crush
zone, so the emphasis is on the use of transverse members between the sills and
cant rails to share the loading between the structural elements on both sides of the
vehicle. Within the doors themselves, horizontal beams the ends of which are
securely fixed to the front and rear frame members of each door are widely used.
However, it is difficult to make them stiff enough to help much unless the frame
and especially its waist and bottom rails are very stiff, so that vertical or diagonal
beams can be fixed to them to support the centre of the horizontal ones. The longer
the door, the more intractable is the problem. Of particular importance is that the
B-pillar be strong enough to prevent it and, with it, both doors from being pushed
inwards in a side impact situation.
PASSIVE SAFETY
In general, if the central portion of the outer panel of the door is thrust
inwards, it will tend to pull not only its front and rear edges, but also the
waist and bottom rails towards each other. Consequently, all these
members must be adequately stiff. Another measure that has been
adopted, for example by Volvo, is to fill the space between the outer and
inner panels of the door with a plastics honeycomb. If the hexagonal
elements of the honeycomb are fairly thick, the filling as a whole will
offer significant resistance to penetration. Moreover, it also transfers
some of the loading radially outwards to the door frame members and
thus further reduces the tendency towards penetration of the door. It
would appear, however, that structural stiffening alone will not be
sufficient to satisfy future legislation, so the installation of side air bags
to supplement the door stiffening measures will probably be
inescapable. Arm rests which could be forced against the vulnerable
areas of the lower ribs of the occupants, should not be installed.
PASSIVE SAFETY
In general, if the central portion of the outer panel of the door is thrust
inwards, it will tend to pull not only its front and rear edges, but also
the waist and bottom rails towards each other. Consequently, all these
members must be adequately stiff. Another measure that has been
adopted, for example by Volvo, is to fill the space between the outer
and inner panels of the door with a plastics honeycomb. If the
hexagonal elements of the honeycomb are fairly thick, the filling as a
whole will offer significant resistance to penetration. Moreover, it also
transfers some of the loading radially outwards to the door frame
members and thus further reduces the tendency towards penetration
of the door. It would appear, however, that structural stiffening alone
will not be sufficient to satisfy future legislation, so the installation of
side air bags to supplement the door stiffening measures will probably
be inescapable. Arm rests which could be forced against the vulnerable
areas of the lower ribs of the occupants, should not be installed.
ÇARPIŞMA TESTLERİ
NCAP Çarpışma Testi ve Derecelendirme
Günümüzde güvenlik bir aracın satışında eskiye oranla daha önemlidir. Müşteriler için
satış kararının en belirleyici unsurudur. Müşterilerin özel araç modellerinin
performansına bağlı olarak güvenilir ve eksiksiz bir biçimde karşılaştırmalı bilgilere
ulaşmaları önemlidir. Kanunen tüm yeni araç modelleri satılmadan önce belirli
güvenlik testlerinden geçmelidir. Yine de yönetmelik yeni araçların güvenliği için
asgari hukuki bir standart belirler, üreticileri bu asgari gereksinimlerin üzerine
çıkma hususunda cesaretlendirme görevi Euro ve Ulusal Otoban Trafik Emniyeti
Kurumu (NHTSA) Yeni Araç Değerlendirme Programı'na (NCAP) aittir.
Önemli Not: Test prosedürleri açısından Euro ve NHTSA arasında farkların olduğunu
unutmayın.
Ön darbe testi: Ön darbe testi yönetmelik esasına göre Avrupa Geliştirilmiş Araç
Güvenliği Kurulu tarafından geliştirilmiştir, fakat darbe hızı 8 km/h artırılmıştır. Ön
darbe 64 km/h'de (40 mil/h) gerçekleştirilir, araç dengelenmiş deforme olabilen
bariyere çarpar. Cansız mankenler üzerinden alınan değerler, ön koltuktaki yolcuların
güvenliği belirlemek için kullanılır.
Yan darbe testi: Darbe 50 km/h'de (30 mph) gerçekleşir Yan darbe testi simülasyonu
için aracın sürücü tarafına doğru ön kısmı deforme olabilen bir vagon çekilir. Sürücü
güvenliğini belirlemek için manken üzerinden alınan değerler kullanılır.
NCAP Çarpışma Testi ve Derecelendirme
Çarpışma Testi Mankenleri
Cansız mankenler üzerinde defalarca doğrudan çarpışma gerçekleştirilir.
Mankenlerin görevi hayatidir: Kaza simülasyonları, bir kaza esnasında
olası yaralanmaların tümünü göstermek için araç içindeki bir sürücü ve
yolcu ile gerçekleştirilir. Mankenler normal sürücü ve yolcu değildir: Çelik
gövdelidir, duyarlı bir ekipmanla donatılmıştır ve lastikle kaplıdır. Mankenler,
çarpışma esnasında ne olduğu hakkında hayati bilgiler sağlar. Uzuvları tek
tek açıklayan kılavuz, verinin nasıl sağlandığını açıklar.
Baş: Mankenin başı alüminyumdan yapılmıştır ve içi lastikle
doldurulmuştur. İçinde çarpışma esnasında beynin maruz kalabileceği
kuvvetler ve hızlanma verilerini gösteren her biri dik açıyla yerleştirilmiş üç
adet hız ölçer vardır.
Boyun: Çarpma esnasında baş ileriye ve geriye doğru hareket ettiğinde,
boyun üzerindeki bükülme, kopma ve eğilme kuvvetlerini tespit eden
cihazlar vardır.
Kollar: Kollarda herhangi bir alet bulunmaz. Çarpışma testinde kollar
kontrolsüz olarak sallanır, ciddi yaralanmalar nadir görülmesine karşın
kollar için tam bir koruma sağlamak zordur.
Göğüs (ön darbe): Çelik kaburgaya ön darbe esnasında göğüs kafesinin esnemesini
kaydeden bir cihaz takılmıştır. Örneğin emniyet kemerlerinden gelen gibi göğüs
üzerindeki kuvvet büyük olduğunda yaralanma meydana gelir.
Göğüs (yan darbe):Yan darbe mankeninin göğsü diğerlerinden farklıdır, göğüs
basıncını ve bu basıncın hızını kaydetmek için üç kaburga ölçülür.
Karın: Mankene, pelvis kemerine yerleştirilen göstergeler kullanılarak karında
yaralanmaya neden olabilecek kuvvetleri kaydeden sensörler yerleştirilmiştir. Kırığa
veya kalça çıkığına neden olabilen yanal kuvvetleri kaydeder.
Üst Bacak: Bu bölüm pelvis, uyluk kemiği (uyluk) ve dizden oluşur. Uyluk
kemiğindeki yük hücreleri; kırığın veya kalça çıkığının görülebileceği kalça eklemi
dahil tüm bölümlerde yaralanmaya neden olabilecek önden çarpmalar hakkında veri
saptar. Özellikle alt panele çarptığında mankenin dizlerinden iletilen kuvveti
ölçmek için bir 'dizlik' kullanılır.
Alt Bacak: Mankenlerin bacaklarının içerisine takılan göstergeler, kaval kemiğinin
(incik kemiği) ve fibulanın (dizi ayak bileğine bağlar) yaralanma riskiyle birlikte
bükme, kopartma ve eğilme kuvvetlerini de hesaplar. Ön darbe esnasında ayak ve
dizlerin yaralanma riski, sürücünün ayak bölmesindeki esneme ve geriye doğru
hareketi ölçüldükten sonra belirlenir.
Boyun, ön darbe mankeni
Göğüs, yan darbe manken
The most widely used vehicle safety systems
worldwide are those modeled after the New
Car Assessment Program (NCAP), introduced
by the National Highway Traffic Safety
Administration (NTHSA) in the U.S in 1979.
This program has branched into several
regional programs including Australia and
New Zealand (ANCAP), Latin America (Latin
NCAP), China (C-NCAP) and Europe (Euro
NCAP).
David Egertz, Sohrab Kazemahvazi, Stefan Hallström, “Novel Safety Requirements and Crash Test Standards for Light-Weight Urban Vehicles”, Stockholm, 2011-01-28
Crash tests on cars in the European market are most often tested according to
the Euro NCAP standards. These tests are not mandatory, so vehicles are
either tested on initiative by Euro NCAP or by the manufacturers themselves
[1]. The tests used are based on the Whole Vehicle Type Approval
(ECWVTA) directive by the European Commission [7], which dictates the
requirements for making a vehicle legal for sale within the European Union.
Euro NCAP’s performance requirements are higher than those described in
the directive, and are constantly increasing to inspire safety improvements.
Safety ratings are reported by star ratings.
David Egertz, Sohrab Kazemahvazi, Stefan Hallström, “Novel Safety Requirements and Crash Test Standards for Light-Weight Urban Vehicles”,
The Euro NCAP tests have undergone several evaluations to estimate the
effectiveness of the test procedures. These studies show that every added
star represents a 12% reduction in collision fatality rates [9].
The crash tests conducted by Euro NCAP are [10]:
• Frontal impact into a deformable offset barrier at 64 km/h.
• Car to car side impact into the driver’s door at 50 km/h.
• Pole side impact into rigid pole at 29 km/h.
• Pedestrian impact at 40 km/h.
• Rear impact whiplash injury test
These tests include child protection tests and the implementation of
active safety assisting equipment like electronic stability control (ESC), seat
belt reminders, speed limitation devices and anti-lock braking systems (ABS)
[10].
Crash test scores are then declared with respect to and weighed according to:
• 50% - Adult occupant assessment
• 20% - Child occupant assessment
• 20% - Pedestrian assessment
• 10% - Safety assist assessment
Figure 1: Euro NCAP’s weighing of test results from each assessment protocol
to obtain the final score.
Safety Assisting Equipment
Unlike all other Euro NCAP testing
procedures, the safety assist functions
do not require any destructive testing.
The aim with the protocol is promote
standard fitment of safety assisting
equipment such as Electronic Stability
Control (ESC), Anti-Locking Brakes
(ABS), Seat Belt Reminders and Speed
Limitation Devices. The scoring of these
systems is based on primarily the
fitment of such equipment and
secondary on the performance of this
equipment.
Frontal Impact
Euro NCAP frontal impact tests are performed at an impact velocity of 64
km/h, 8 km/h higher than limits legislated by ECWVTA. The test shall
represent two similar cars colliding with each other in a 40% offset impact,
which is considered as the most common traffic accident resulting in severe
injury or death. 40% meaning that the 40% of the vehicles frontal structure is
struck in the impact.
Figure A.2 Frontal impact crash test setup
Frontal Impact
The protection level is assessed using a frontal impact crash test dummy
which measure accelerations, forces, deflections and deformations.
Çarpışma
testlerinde Pelvis: Leğen kemiği
kullanılan
mankenler Femur: Uyluk kemiği
(Dummy)
Tibia: Kaval kemiği
Yapılan çarpışma testlerinde
oluşabilecek
yaralanmaları
belirleyebilmek için elektronik
sensörlerle donatılan son derece
gelişmiş mankenler (dummy)
kullanılmaktadır. Aynı zamanda
üretici firmaların önerdiği çocuk
koltukları da araca yerleştirilip
çarpışmalarda
çocukları
koruyup
korumadığı Crash test dummy results are presented
using a five step scale.
belirlenmektedir.
Reading Text:
In a frontal collision, kinetic energy is absorbed through deformation of
the bumper, the front of the vehicle, and in severe cases the forward section
of the passenger compartment (dash area). Axles, wheels (rims) and the
engine limit the deformable length. Adequate deformation lengths and
displaceable vehicle aggregates are necessary, however, in order to
minimize passenger-compartment acceleration.
Damage to the passenger compartment should be minimized. This
concerns primarily
• dash area (displacement of steering system, instrument panel, pedals,
toe-panel intrusion),
• underbody (lowering or tilting of seats),
• the side structure (ability to open the doors after an accident).
Acceleration measurements and evaluations of high-speed films enable
deformation behavior to be analyzed precisely. Dummies of various sizes
are used to simulate vehicle occupants and provide acceleration figures for
head and chest as well as forces acting on thighs.
Automotive Handbook
Car to Car Side Impact
Car side impact tests are performed by using a movable deformable
barrier as seen in Figure. The impact is centered at the driver’s door
at an impact velocity of 50 km/h.
Figure : Car to car side impact test setup.
Car to Car Side Impact
The aim with the test procedure is to assess any intrusion and occupant
protection obtained from the cars side structure, but also to encourage the
implementation of side airbags. To assess the occupant protection a side impact
test dummy is used. Measures that are recorded are accelerations, forces,
moments and deflections.
Thoraks: Göğüs kafesi
Rib: Kaburga kemiği
Figure: Side impact crash test dummy rating.
Pole Side Impact
The pole side impact tests goal is to
encourage the fitting of head
protection devices such as side
impact head or curtain airbags and
padding. Since the pole is relatively
narrow, 10’’, or 254 mm, major
intrusion is a common result. The
test is performed by propelling the
vehicle into a rigid pole at 29
km/h, representing the vehicle
skidding into a pole or a tree, see
Figure.
Since 2009 this test is mandatory in
the assessment process, and
focuses on head, chest and
abdomen protection. Before 2009 it
was
an
optional
test
for
manufacturers to demonstrate the
efficiency of their head protection
features.
Figure: Pole side impact test setup
Pole Side Impact
Figure: Pole side impact crash test dummy rating.
Pedestrian Protection
The pedestrian protection protocol has been a part of Euro NCAP since the start in
1997. Up to 2009 this test had a separate star rating but is now an integral part of the
overall rating scheme seen in Figure A.1. Euro NCAP performs a series of tests to
evaluate the pedestrian protection for both adult and child pedestrians. During the
tests individual vehicle components are assessed to have a better control of the
pedestrian impact locations. A legform is used to test the protection of the lower leg
towards the front bumper, an upper legform to test the protection towards the
leading edge of the bonnet and a child and adult headform to test the protection
towards the bonnet top area and windscreen. The tests shall represent an impact
velocity of 40 km/h.
Figure: Pedestrian impact test setup and rating system.
Whiplash Protection
The whiplash testing procedure is not a crash test involving the actual vehicle, but
instead the seat and head rest assembly. The test is performed with the use of a crash
sled on which the vehicle seat with a crash test dummy is fitted. The sled is then
subjected to three different crash pulses with varying severity; low, medium and
high. The low severity pulse accelerates the sled to approximately Dv=16 km/h in
100ms, and the high severity pulse to approximately Dv=25 km/h in 100ms [23][36].
These pulses are derived from both real world crashes and insurance industry
research. The whole concept of whiplash injury is not yet entirely understood,
especially the injury causing mechanisms of it, but the high frequency of this injury
type has motivated Euro NCAP to include it into its adult occupant protection
protocol since January 2009.
Figure: Rear impact whiplash rating.
Child Protection
The child occupant protection is a part of the frontal and car-to-car side impact testing
procedures, but also addresses usability of the child restraints (CRS). Since it has shown
that many child restraint users fail to secure the restraint safely to the car, Euro NCAP
encourage improvements to child restraint design and the installation of standardized
mountings such as ISOFIX. In the testing, dummies representing 18 month and 3 year
old children are used (Figure 1-2), and the score depends on the child seats dynamic
performance in frontal and side impact tests. Additionally, fitting instructions, airbag
warning labels and the vehicles ability to accommodate the child restraint safely is also
included in the overall scoring.
Figure: Child protection testing
rating scheme of 18 month old child.
Figure: Child protection testing
rating scheme of 3 year old child.
Child Protection
A- Dynamic Assessment
B- Frontal Impact
C- Side Impact
Child Protection
D- Child Restraint Based Assessment
E- Vehicle Based Assessment
ÖZET….
Fig.: Some of the tests done by manufacturers to ensure that the occupants of their
vehicles will be, so far as is practicable, safe in the event of an accident. At (a) is the
simple basic zero offset frontal impact, at (b) is a 30 offset, at (c) a 40% offset and at
(d) a pole impact test. A side impact test for representing an impact between two
vehicles moving along lines at right angles to each other is shown at (e) while, at (f ), the
vehicle that is struck is stationary. Finally, a rear end impact test is shown at (g).

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