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Described in this paper is a component test methodology to evaluate the door trim armrest performance in an Insurance Institute for Highway Safety (IIHS) side impact test and to predict the SID-IIs abdomen injury metrics (rib deflection, deflection rate and V*C). The test methodology consisted of a sub-assembly of two SID-IIs abdomen ribs with spine box, mounted on a linear bearing and allowed to translate in the direction of impact. The spine box with the assembly of two abdominal ribs was rigidly attached to the sliding test fixture, and is stationary at the start of the test. The door trim armrest was mounted on the impactor, which was prescribed the door velocity profile obtained from full-vehicle test. The location and orientation of the armrest relative to the dummy abdomen ribs was maintained the same as in the full-vehicle test.

Vehicle safety systems may use occupant physiological information, e.g., occupant heights and weights to further enhance occupant safety. Determining occupant physiological information in a vehicle, however, is a challenging problem due to variations in pose, lighting conditions and background complexity. In this paper, a novel occupant height estimation approach is presented. Depth information from a depth camera, e.g., Microsoft Kinect is used. In this 3D approach, first, human body and frontal face views (restricted by the Pitch and Roll values in the pose estimation) based on RGB and depth information are detected. Next, the eye location (2D coordinates) is detected from frontal facial views by Haar-cascade detectors. The eye-location co-ordinates are then transferred into vehicle co-ordinates, and seated occupant eye height is estimated according to similar triangles and fields of view of Kinect.

Crash safety is a complex engineering field wherein a good understanding of energy attenuation capabilities due to an impact of various components and between different/adjacent components in the context of the vehicle environment is imperative. During a frontal impact of the vehicle, an occupant’s lower extremity tends to move forward and could impact one or more components of the instrument panel assembly. A glove box component design may have an influence on occupant’s lower extremity injuries when exposed to the occupant’s knees during a frontal impact. The objective of the present numerical study was to develop a novel glove box design with energy absorbing ribs and then comparing the results with the glove box with a knee airbag (KAB) design to help reduce anthropomorphic test device (ATD) lower leg responses.

An experimental study was conducted using a dynamic rollover component test system (ROCS) to study the effects of activating a pyro-mechanical buckle pre-tensioner and an electric retractor on the driver and front right passenger head and pelvis excursions. The ROCS is a unique system capable of producing vehicle responses that replicate four distinct phases of a tripped rollover: trip initiation, roll initiation, free-flight vehicle rotation, and vehicle to ground contact. This component test system consists of a rigid occupant compartment derived from a mid-size SUV with complete 1st row seating and interior trim, a simulated vehicle suspension system and an elastic vehicle-to-ground-contact surface. The ROCS system was integrated with a Deceleration Rollover Sled (DRS). Dynamic responses of the ROCS system, including both the rigid compartment and occupant, were measured and recorded.

In December 2015, the National Highway Traffic Safety Administration (NHTSA) published a Request for Comments on proposed changes to the New Car Assessment Program (NCAP). One potential change is the addition of a frontal oblique impact (OI) crash test using the Test Device for Human Occupant Restraint (THOR). The resultant acetabulum force, which is a unique and specifically defined in the THOR dummy, will be considered as a new injury metric. In this study, the results of ten OI tests conducted by NHTSA on current production mid-sized vehicles were investigated. Specifically, the test data was used to study the lower extremity kinematics for the driver and front passenger THOR dummies. It was found that the acetabulum force patterns varied between the driver and passenger and between the left leg and the right leg of the occupants. The maximum acetabulum force can occur either on the left side or right side of a driver or a front passenger in an OI event.

Assembly operators are rarely observed performing one-handed tasks where the unutilized hand is entirely inactive. Therefore, this study was designed to determine the forces applied to supporting hands, by automotive assembly operators, during common one-handed tasks such as hose installations or electrical connections. The data were computed as a percentage of body weight and a repeated measures analysis of variance (ANOVA) (p<0.05) was conducted. Supporting hand forces were observed to range from 5.5% to 12.1% of body mass across a variety of tasks. The results of this study can be used to account for these supporting hand forces when performing a biomechanical/ergonomic analysis.

In CAE analysis of cylinder bore distortion, valve seat distortion, valve guide-to-seat misalignment and cam bore misalignment, nodal displacements on the cylinder bore inner surface and on the gage lines of valve seats, valve guides and cam bores are typically output. Best fit cylinders, best fit circles and best fit lines are computed by utilizing the output displacements of the deformed configuration. Based on the information of the best fit geometry, distortions and misalignments are assessed. Some commercial and in-house software is available to compute the best fit cylinders, best fit circles and best fit lines. However, they suffer from the drawback that only one best-fit geometry can be computed at a time. Using this kind of software to assess distortions and misalignments of engine components would be tedious and prone to error, since data transfer as well as the intermediate computation has to be done by hand, and the process is not automatic.

This paper examines the neck tension force (Fz) of the BioRid II dummy in the IIHS (Insurance Institute of Highway Safety) rear impact mode. The kinematics of the event is carefully reviewed, followed by a detailed theoretical analysis, paying particular attention to the upper neck tension force. The study reveals that the neck tension should be approximately 450N due to the head inertia force alone. However, some of the tests conducted by IIHS had neck tension forces as high as 1400N. The theory of head hooking and torso downward pulling is postulated in the paper, and various publicly available IIHS rear impact tests are examined against the theory. It is found in the analysis that in many of those tests with high neck tension forces, the locus of the head restraint reaction force travels on the dummy's skull cap, and eventually moves down underneath the skull cap, which causes “hooking” of the head on the stacked-up head restraint foam.

Vehicle motion prior to a rollover can influence an occupant's position in the vehicle. Lateral deceleration prior to a tripped rollover may cause the occupant to move outboard. This outboard motion may have several effects on the occupant such as, repositioning the occupant with relation to the seat and seat restraint, and allowing the occupant's head to travel further into the side curtain deployment zone. To reduce occupant lateral motion, the effectiveness of applying tension to the seatbelt was evaluated. The evaluation consisted of two test conditions simulating vehicle lateral motion prior to a trip using a Deceleration Rollover Sled [1]. The test conditions were designed to ensure a vehicle experiences a period of pure lateral motion before the onset of a lateral trip. A standard seat belt combined with various means of applying tension and activated at different times during the test were evaluated.

Blunt impacts to the back of the torso can occur in vehicle crashes due to interaction with unrestrained occupants, or cargo in frontal crashes, or intrusion in rear crashes, for example. Six pendulum tests were conducted on the back of an instrumented 50th percentile male Hybrid III ATD (Anthropomorphic Test Device) to determine kinematic and biomechanical responses. The impact locations were centered with the top of a 15-cm diameter impactor at the T1 or at T6 level of the thoracic spine. The impact speed varied from 16 to 24 km/h. Two 24 km/h tests were conducted at the T1 level and showed repeatability of setup and ATD responses. The 16 and 24 km/h tests at T1 and T6 were compared. Results indicated greater head rotation, neck extension moments and neck shear forces at T1 level impacts. For example, lower neck extension was 2.6 times and 3.8 times greater at T1 versus T6 impacts at 16 and 24 km/h, respectively.

Automotive manufacturing presents unique challenges for ergonomic analysis. The variety of tasks and frequencies are typically not seen in other industries. Moving these challenges into the realm of digital human modeling poses new challenges and offers the opportunity to create and enhance tools brought over from the traditional reactive approach. Chiang et al. (2006) documented an enhancement to the Siemen's Jack Static Strength Prediction tool. This paper will document further enhancements to the ErgoSolver (formerly known as the Ford Static Strength Prediction Solver).

This study examines the biofidelity, repeatability, and reproducibility of various anthropomorphic devices in rear impacts. The Hybrid III, the Hybrid III with the RID neck, and the TAD-50 were tested in a rigid bench condition in rear impacts with ΔVs of 16 and 24 kph. The results of the tests were then compared to the data of Mertz and Patrick[1]. At a AV of 16 kph, all three anthropomorphic devices showed general agreement with Mertz and Patrick's data [1]. At a AV of 24 kph, the RID neck tended to exhibit larger discrepancies than the other two anthropomorphic devices. Also, two different RID necks produced significantly different moments at the occipital condyles under similar test conditions. The Hybrid III and the Hybrid III with the RID neck were also tested on standard production seats in rear impacts for a AV of 8 kph. Both the kinematics and the occupant responses of the Hybrid III and the Hybrid III with the RID neck differed from each other.

This study applies a detailed finite element model of the human body to simulate occupant knee impacts experienced in vehicular frontal crashes. The human body model includes detailed anatomical features of the head, neck, chest, thoracic and lumbar spine, abdomen, and lower and upper extremities. The material properties used in the model for each anatomic part of the human body were obtained from test data reported in the literature. The total human body model used in the current study has been previously validated in frontal and side impacts. Several cadaver knee impact tests representing occupants in a frontal impact condition were simulated using the previously validated human body model. Model impact responses in terms of force-time and acceleration-time histories were compared with test results. In addition, stress distributions of the patella, femur, and pelvis were reported for the simulated test conditions.

NHTSA estimates that more than half of the lives saved (168,524) in car crashes between 1960 and 2002 were due to the use of seat belts. Nevertheless, while seat belts are vital to occupant crash protection, safety researchers continue efforts to further enhance the capability of seat belts in reducing injury and fatality risk in automotive crashes. Examples of seat belt design concepts that have been investigated by researchers include inflatable, 4-point, and reverse geometry seat belts. In 2011, Ford Motor Company introduced the first rear seat inflatable seat belts into production vehicles. A series of tests with child and small female-sized Anthropomorphic Test Devices (ATD) and small, elderly female Post Mortem Human Subjects (PMHS) was performed to evaluate interactions of prototype inflatable seat belts with the chest, upper torso, head and neck of children and small occupants, from infants to young adolescents.

The abdomen is the second most commonly injured region in children using adult seat belts, but engineers are limited in their efforts to design systems that mitigate these injuries since no current pediatric dummy has the capability to quantify injury risk from loading to the abdomen. This paper develops a porcine (sus scrofa domestica) model of the 6-year-old human's abdomen, and then defines the biomechanical response of this abdominal model. First, a detailed abdominal necropsy study was undertaken, which involved collecting a series of anthropometric measurements and organ masses on 25 swine, ranging in age from 14 to 429 days (4-101 kg mass). These were then compared to the corresponding human quantities to identify the best porcine representation of a 6-year-old human's abdomen. This was determined to be a pig of age 77 days, and whole-body mass of 21.4 kg.

The biomechanical behavior of 4-point seat belt systems was investigated through MADYMO modeling, dummy tests and post mortem human subject tests. This study was conducted to assess the effect of 4-point seat belts on the risk of thoracic injury in frontal impacts, to evaluate the ability to prevent submarining under the lap belt using 4-point seat belts, and to examine whether 4-point belts may induce injuries not typically observed with 3-point seat belts. The performance of two types of 4-point seat belts was compared with that of a pretensioned, load-limited, 3-point seat belt. A 3-point belt with an extra shoulder belt that “crisscrossed” the chest (X4) appeared to add constraint to the torso and increased chest deflection and injury risk. Harness style shoulder belts (V4) loaded the body in a different biomechanical manner than 3-point and X4 belts.

One thing that is very important in a carmaker company is its know-how built during all its life. Such an experience allows, for instance, to correlate the customer expected product life with accelerated tests procedures. When it comes to cars, it is usual to have correlated proving routes in such way that if a prototype can take a number of passing in the proving ground without failure, it is unlikely the car is going to fail during a regular life. In the other hand, if a failure at determined percentage of the test happens, it is predictable that the same failure shows up at the same percentage of the product design life. This paper proposes a methodology based on the SxN fatigue theory to solve durability issues observed in correlated durability tests.

Did you had opportunity to hear any unpleasant noise when closing some vehicle door? In some cases reminds a metallic touch condition, in other cases reminds several components loose inside the door. The fact is that this kind of noise is definitely unpleasant to the human ears. The good news is that this undesirable condition can be solved easily through of add a soft bumper in the striker; however, needs to pay attention in the material properties and tolerance stack-up conditions to avoid generate side effect, like as high door closing efforts, break parts, lose parts, etc.

The way a subframe for an independent rear suspension attaches to a unibody vehicle is critical for its NVH performance. The force path from the control arms to the body may, in some cases, pass through spots where some body vibration modes with relatively high acoustic radiation efficiency are excited, generating undesired peaks at some frequencies for point and transfer mobilities, as well as for acoustic transfer functions from the subframe to the driver's and passenger's ears. This paper describes a case study of an initial design for a subframe, where a vibration mode of the vehicle's rear underfloor panel was particularly strongly excited causing unacceptable both acoustic and vibrational behaviours, is modified through the evaluation of point mobility curves, as well as acoustic transfer functions, both obtained via finite elements method.

A comparison of the 50th percentile male THOR-LX and Hybrid III 50th percentile male dummy lower leg was conducted via component and full scale barrier testing. In the component tests, isolated THOR-LX and Hybrid III lower legs were impacted in two different test set-ups where the tibia was impacted at three different impact points. The foot without a shoe was impacted in two different test set-ups at six different impact points. A shoe impact study was also conducted to determine the effect of a shoe on the results and to determine how many impacts a shoe can withstand at each point before properties of the shoe begin to change. For these tests, the THOR-LX and Hybrid III lower legs were repeatedly impacted at four different points on the foot with a shoe. For the full scale barrier testing, the THOR-LX or Hybrid III lower legs were attached to a belted Hybrid III 50th percentile male dummy. The dummy was positioned in a compact car for each test.