2. I. Research background:
In view of vehicle manufacturers made vehicle’s performance better than before.
Accidents of vehicle were grown up so fast and more serious by observing the
NHTSA’s report“Traffic Safety Facts 1995＂. So more and more countries set up the
regulation and required the new car should pass the regulation. In addition, some
nonprofit and communications organizations were emboldened, funded by auto
Industry or government. For example: USNCAP, EuroNCAP, J-NCAP, A-NCAP and
C-NCAP. However, NCAP’s goals are to improve occupant safety by providing
market incentives for vehicle manufacturers to voluntarily design vehicles with
improved crashworthiness and provide independent safety information to aid
consumers in marking comparative vehicle purchase decisions.
In general, the vehicle safety could be divided in to two parts: active safety and
passive safety. Active safety means when the sensors detect the accident will happen;
the safety gear should be fired up, for example: seatbelt. On the contrary, when
accidents happen the safety gear was fired up, it was called passive safety, for
example: air bags. As my work researched the air bag, I will focus on air bag design.
Why did we research and develop the air bag? According to National
Transportation Safety Board, the benefits of air bags can be examined from different
aspects: their effectiveness in reducing the risk of fatal injuries, their effectiveness in
reducing the severity of nonfatal injuries, and the performance of various air bag
technologies. The National Highway Traffic Safety Administration (NHTSA) uses
data from its Fatality Analysis Reporting System (FARS) to estimate the reduction in
fatality risk from air bags. According to analyses based on FARS data, air bags reduce
the overall fatality risk by 11 percent for drivers in passenger vehicles and by 13.5
percent for passengers over age 13. NHTSA uses the National Automotive Sampling
System (NASS) to evaluate the effectiveness of air bags in reducing the likelihood of
sustaining a moderate or greater injury. The NASS analysis found that air bags
combined with the lap/shoulder belt provide the greatest injury protection. The injury
reducing effectiveness of the air bag alone was not significantly better than being
unrestrained.
Because it was useful to provide protection in vehicle accident, so many vehicle
manufactures developed and improved air bag and set it up in vehicle. For this reason,
my proposal will address new air bag to improve traditional air bag by new material
and new manufacturing technology. In new material, using the environmental material,
3. Thermoplastic Polyurethane, replaced the Nylon66 to do the cushion. It could reduce
problem of waste material’s recycling and make the price of the cushion down. In
new manufacturing technology, it used the High-Frequency Plastic Welding Machine
to make the cushion. It could replace the traditional manufacturing technology, using
Multi Needle Flat Sewing Machine to sew the cushion, and save manufacturing time
and overcome gas out of cushion from sewing parts. Because it overcame gas out of
cushion, so it could provide the time of protection better than traditional air bag. In
addition to provide the time of protection, this proposal will use CAE software to
prove the Head Injury Criterion (HIC) better than before.
II. The aim of this research project:
The goal of my proposal is divided into three parts: used environmental materials,
new air bag protection better than traditional airbags, as well as the price of new air
bags being cheaper than traditional ones.
A. Environmental Material:
In general, cushion was manufactured in nylon 66, it couldn’t be
decomposed by itself and needed someone to recycle and dealt with it. In
this proposal, it will research and develop the Environmental Material,
Thermoplastic Polyurethane, to make cushion. Because this material could
be decomposed by itself, so manufactures could reduce the problem of
waste material’s recycling and the price of recycled process.
B. Better Protection:
The problem of protection was the most important in air bag designed.
In the traditional air bag, when the module was stared, it would be inflated
and maintained inflation about 50 milliseconds. If the vehicle was occurred
rollover, the time of air bag’s protection couldn’t satisfy the rollover’s time.
But the new air bag could provide the protection over 6 second, so it could
easily satisfy the rollover. Beside the protected time, it could use CAE
software to simulate the Head Injury Criterion value. By the computer
simulating score, we could understand the Head Injury Criterion value
better than traditional air bag. In fig1, the red and blue lines presented the
simulate value of protection, Head Acceleration, in new and traditional air
bag module respectively. By the graph, we could get the dummy contacted
the air bag in 45 millisecond. At that time, the head acceleration value of
red was low than blue about 50 m/s2
. So, we could understand the HIC
4. value of new air bag better than tradition.
C. Cheaper Price:
In general, the cushion was made by nylon 66’s cloth, and the cloth
was made by nylon 66’s plastic. In process of manufacturing cloth, it
needed many textile machines to do it, and the textile machine was very
expensive. Beside of textile machine, when producing the cushion, it
needed Laser Cutting machine and Sewing machine to do it. So, it wasted
much time and machine’s cost. In this proposal, it used Plastic Extruders or
Plastic Multi Layer Blown Film machine to make TPU film and
High-Frequency Plastic Welding machine to create cushion. Due to it didn’t
need many manufacturing machine, the cushion’s price would be cheaper
than before and make the cushion fast than before.
I believed it was worth to research and develop this proposal by using new
material and new manufacturing technology.
III. Research Methodology:
In this proposal, I will divide it into three parts: new material, manufacturing
technology and testing method.
A. New material
1. TPU film:
In this area, I will use Thermoplastic Polyurethane plastic and
the Plastic Extruders or Plastic Co-Extruders to do the film. It is
very important to pick up the TPU plastic’s characteristic. Because
the specification of ISO 12097-2 shall be passed low and high
temperature test, the TPU plastic have a trouble of satisfied low
and high temperature test at the same time.
2. TPE film:
I will use Nylon and Thermoplastic Elastomer plastics to
5. compound and make the film by Plastic Twin Screw Extruders and
Multi Layer Blown Film Machine. It is a very important problem to
pick them up compounding. If Nylon and TPE don’t match well, it
will have trouble in using Plastic Twin Screw Extruders.
B. Manufacturing technology
In doing the cushion, I will use High-Frequency Plastic Welding
Machine to make the cushion. This machine needs a pattern to do a cushion.
It is important to adjust the machine electric current and maintain the
pattern level.
C. Testing method
In this area, it could divide two parts: simulate analysis and
experiment.
1. Simulate analysis:
By using LS-DYNA or MADYMO software, it could provide
general result and this result could help us to modify the cushion
profile. According to this result, we could know the protection of
air bag module. It also provided better method to improve the air
bag module. The result of simulate analysis must be compared with
experiment. It needed experiment to valid the correction of
simulate result.
2. Experiment:
In the experiment, it can be separated to film test and air bag
module test.
a. Film test:
I will refer Requirement Specification for Coated Fabrics
to do this test. It involved: tensile, tearing strength, elongation,
flammability, weight, thickness, tensile and tearing strength
after heat aging, tensile and tearing strength after humidity
aging, tensile and tearing strength after cycle aging etc. It
needs Omnipotence Experimentation Machine and
Programmable Temp. & Humi. Chamber to complete tests.
b. Air bag module test:
In this test, I will refer ISO 12097-2 to do this test and do
head form impact test, body block test to prove the protection.
It needs high-speed photograph camera to catch the
photograph and related testing system to get the HIC value.
6. By high-speed photograph camera, we can get the air bag
module development and decide experiments success or fail.
By the HIC value, we will understand the degree of air bag’s
protection.
IV. Summary:
In this proposal, I address new material and manufacturing technology to make
the air bag module. The new air bag module use environmental material to reduce
environmental problem and provide better protection to reduce the injury in accident
and improve the manufacturing process to decrease the product’s price. Beside of
them, it satisfies the requirement of rollover and can provide protection over 6 second.
It also can overcome the cushion burns occupier by using the cool inflator. I think this
proposal can be carried out. It had more advantage than traditional air bag.
7. V. References:
1. National Transportation Safety Board: Safety Recommendation.
2. Federal Motor Vehicle Safety Standards 208 - Occupant Crash Protection.
3. Federal Motor Vehicle Safety Standards 214 - Side Impact Protection.
4. United Nations Economic Commission for Europe Regulations 12 -
UNIFORM PROVISIONS CONCERNING THE APPROVAL OF
VEHICLES WITH REGARD TO THE PROTECTION OF THE DRIVER
AGAINST THE STEERING MECHANISM IN THE EVENT OF IMPACT.
5. United Nations Economic Commission for Europe Regulations 95 -
UNIFORM PROVISIONS CONCERNING THE APPROVAL OF
VEHICLES WITH REGARD TO THE PROTECTION OF THE
OCCUPANTS IN THE EVENT OF A LATERAL COLLISION.
6. ISO 12097-2:1996“Road vehicles - Airbag components - Part 2: Testing of
airbag modules＂
7. Autoliv: Requirement Specification for Coated Fabrics.
8. Autoliv: Requirement Specification for Uncoated Fabrics.
9. NHTSA: Traffic Safety Facts 1995.
