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Current legform impact test methods using the FlexPLI have been developed to protect pedestrians from lower limb injuries in collisions with low-bumper vehicles. For this type of vehicles, the influence of the upper body on the bending load generated in the lower limb is compensated by setting the impact height of the FlexPLI 50 mm above that of pedestrians. However, neither the effectiveness of the compensation method of the FlexPLI nor the influence of the upper body on the bending load generated in the lower limb of a pedestrian has been clarified with high-bumper vehicles. In this study, therefore, two computer simulation analyses were conducted in order to analyze: (1) The influence of the upper body on the bending load generated in the lower limb of a pedestrian when impacted by high-bumper vehicles and (2) The effectiveness of the compensation method for the lack of the upper body by increasing impact height of the FlexPLI for high-bumper vehicles.

For applying ISO 26262 to motorcycles, controllability classification (C class evaluation) by expert riders is considered an appropriate technique. Expert riders have evaluated commercial product development for years and can appropriately conduct vehicle tests while observing safety restrictions (such as avoiding the risk of falling). Moreover, expert riders can ride safely and can stably evaluate motorcycle performance even if the test conditions are close to the limits of vehicle performance. This study aims to construct a motorcycle C class evaluation method based on an expert rider’s subjective evaluation. On the premise that expert riders can rate the C class, we improved a test procedure that used a subjective evaluation sheet as the concrete C class evaluation method for an actual hazardous event.

Recently there has been a greater awareness of the increased risk of certain injuries associated with air bag deployment, especially the risks to small occupants, often women. These injuries include serious eye and upper extremity injuries and even fatalities. This study investigates the interaction of a deploying air bag with cadaveric upper extremities in a typical driving posture; testing concentrates on female occupants. The goals of this investigation are to determine the risk of upper extremity injury caused by primary contact with a deploying air bag and to elucidate the mechanisms of these upper extremity injuries. Five air bags were used that are representative of a wide range of air bag ‘aggressivities’ in the current automobile fleet. This air bag ‘aggressivity’ was quantified using the response of a dummy forearm under air bag deployment.

Biomechanical data are often assumed to be doubly censored. In this paper, this assumption is evaluated critically for several previously published sets of data. Injury risk functions are compared using simple logistic regression and using survival analysis with 1) the assumption of doubly censored data and 2) the assumption of right-censored (uninjured specimens) and uncensored (injured) data. It is shown that the injury risk functions that result from these differing assumptions are not similar and that some experiments will require a preliminary assessment of data censoring prior to finalizing the experimental design. Some types of data are obviously doubly censored (e.g., chest deflection as a predictor of rib fracture risk), but many types are not left censored since injury is a force-limiting phenomenon (e.g., axial force as a predictor of tibia fracture). Guidelines for determining the censoring for various types of experiment are presented.

Injuries of the Occipitoatlantoaxial (Occ-C2) region (also known as atlanto-occipital injuries) are the most common form of cervical injury in children aged ten years and younger. The crash studied in this paper is unique in that there were three children ages 3, 6 and 7 involved in a frontal crash with a delta V of 28mph with each child receiving a nonfatal Occ-C2 injury of varying degrees. The 3 and 6 year-old children were remarkably similar in height and weight to the 3 and 6 year-old Hybrid III ATD's. Also, unique to this case is the fact that the right rear 6 year-old occupant likely sustained an Occ-C2 injury prior to impact with the frame of the front passenger seat. This crash environment was recreated utilizing MADYMO occupant simulation software. The models for the Hybrid III 3 and 6 year-old ATDs were used to represent the occupants in this crash.

Studies show that the pedestrian population at high risk of injury consists of both young children and adults. The goal of this study is to gain understanding in the mechanisms that lead to injuries for children and adults. Multi-body pedestrian human models of two specific anthropometries, a 6year-old child and a 50th percentile adult male, are applied. A vehicle model is developed that consists of a detailed rigid finite element mesh, validated stiffness regions, stiff structures underlying the hood and a suspension model. Simulations are performed in a test matrix where anthropometry, impact speed and impact location are variables. Bumper impact occurs with the tibia of the 50th percentile adult male and with the thigh of the 6-year-old child. The head of a 50th percentile male impacts the lower windshield, while the 6-year-old child's head impacts the front part of the hood.

The main objective of the present study is to determine experimentally the injury patterns and response of the human thigh in lateral impacts simulating more closely the real impact conditions in car-pedestrian accidents. We conducted in-vitro experiments on thirteen thighs of eight completely intact Post Mortem Human Subjects (PMHSs). The thigh was hit by a ram at a speed of 35 km/h at the mid-shaft of the femur in each completely intact PMHS. Since the effect of cumulative injuries should be avoided, each thigh was impacted only once. Three impact energies were used; 450J, 600J and 700J. The PMHS motion was not constrained so as to simulate the walking posture of a pedestrian. We analyzed the peak values of the impact force of the ram and the femur acceleration. Injury was assessed by dissecting the lower extremities.

The New Car Assessment Program in Japan (JNCAP) was launched in 1995 in order to improve car safety performance. According to this program, installation conditions of safety devices and the results for braking performance and full- frontal crash tests are published every year. Introduction of JNCAP significantly increases the installation rate of safety devices and contributes much in enhancement of safety as seen in the decrease in the average injury severity of drivers and passengers. Side impact and offset frontal crash tests were introduced in 1999 and 2000, respectively. At present, the overall crash safety rating is carried out based on the results of the full-frontal, offset frontal, and side impact tests.

This paper summarizes a future side impact test procedure based on the Japanese presentation at the recent IHRA Side Impact WG meeting. Under current Japanese regulations, the MDB specifications and test procedures were determined based on a market study more than ten years ago. Thus, they may not reflect current automobile characteristics, the actual accident situation, and crash test results. In this study (1) the vehicle types, velocity of striking and struck vehicles, body injury regions, causes of injuries, etc., are reviewed with reference to the latest Japanese side impact accident data. The occupant percentages for the non-struck-side, rear seat and for female occupants as well as the injury levels were analyzed. (2) To determine the MDB specifications, based on data from passenger car models registered in 1998, the curb mass, geometry and stiffness were examined. (3) For factorial analysis, side impact tests were performed as for real accidents.

The Japan New Car Assessment Program (JNCAP) was launched in 1995 in order to improve car safety performance. According to this program, installation conditions of safety devices and the results for braking performance and full- frontal crash test are published every year. The side impact test was introduced in 1999. In 2000, the offset frontal crash test was also introduced. From the viewpoint of such a diversification of the crash tests, an overall assessment method for the safety of cars which reflects road accidents has been demanded. In this study, we have examined a new overall assessment method capable of reflecting the traffic accident situation in Japan using methods employed or planned by USA-NCAP, Euro-NCAP, TUB-NCAP and others as references. As the basic concept, JNCAP conducts three types of crash tests including the full-frontal crash test, offset frontal crash test, and side impact test to assess the dummy injury parameters.

The legform impactor proposed by EEVC/WG17 is composed of a rigid thigh segment and a rigid lower leg segment. Human bone, however, has flexibility, causing some differences between the EEVC rigid legform impactor and the human leg. This research analyzes the influence of the differences (rigid versus flexible) on the injury criteria. It also reanalyzes the upper tibia acceleration with regard to the fracture index. The rigid legform impactor cannot simulate bone bending motion, so the injury criteria should consider the legform rigidity. It means the injury criteria need to include the bone bending effect. From several PMHS test results, the shearing displacement becomes 23 mm and 20 degrees for bending angle including the bone bending effect. However, the bone bending effect will change with the loading conditions. Therefore, to establish a certain injury criteria for a rigid legform impactor is impossible. To solve this problem, a flexible legform impactor seems to be needed.

This paper presents a computational study of the effects of three parameters on the resulting thoracic injury criteria in side impacts. The parameters evaluated are a) door velocity-time (V-t) profile, b) door interior padding modulus, and c) initial door-to-occupant offset. Regardless of pad modulus, initial offset, or the criterion used to assess injury, higher peak door velocity is shown to correspond with more severe injury. Injury outcome is not, however, found to be sensitive to the door velocity at the time of first occupant contact. A larger initial offset generally is found to result in lower injury, even when the larger offset results in a higher door velocity at occupant contact, because the increased offset results in contact later in the door V-t profile - closer to the point at which the door velocity begins to decrease. Cases of contradictory injury criteria trends are identified, particularly in response to changes in the pad modulus.

Computer simulations, dummy experiments with a new enhanced upper extremity, and small female cadaver experiments were used to analyze the small female upper extremity response under side air bag loading. After establishing the initial position, three tests were performed with the 5th percentile female hybrid III dummy, and six experiments with small female cadaver subjects. A new 5th percentile female enhanced upper extremity was developed for the dummy experiments that included a two-axis wrist load cell in addition to the existing six-axis load cells in both the forearm and humerus. Forearm pronation was also included in the new dummy upper extremity to increase the biofidelity of the interaction with the handgrip. Instrumentation for both the cadaver and dummy tests included accelerometers and magnetohydrodynamic angular rate sensors on the forearm, humerus, upper and lower spine.

Guidelines with regard to the body strength of buses have been drawn up in Japan. We now pass to the second step in research to assure the greater safety of bus crews and passengers by launching a study on further reduction of collision injuries to bus occupants. As a way to reduce such passenger injuries, our focus is the optimization of energy absorption, the arrangement of equipment on the passenger seat back, the seat frame construction, mounting and so on. The study was conducted using an experimental method together with FEM computer simulation. The findings from a sled impact test simulating a seat in a bus in a frontal collision are stated as follows. 1.Further consideration should be given to the present conventional ELR two-point seat belt. 2.One way to reduce passenger injury is to optimize the space between seats.

ISO 26262 was established in 2011 as a functional safety standard for road vehicles. This standard provides safety requirements according to ASIL (Automotive Safety Integrity Level) in order to avoid unreasonable residual risk caused by malfunctioning behavior of electrical and/or electronic systems. The ASIL is determined by considering the estimate of three factors including injury severity. While applicable only to passenger cars at present, motorcycles will be included in the scope of application of ISO 26262 in the next revision. Therefore, our previous study focused on severity class evaluation for motorcycles. A method of classifying injury severity according to vehicle speed was developed on the basis of accident data. In addition, a severity table for motorcycles was created using accident data in representative collision configurations involved with motorcycles in Japan.

Fatalities resulting from vehicle rollover events account for over one-third of all U.S. motor vehicle occupant fatalities. While a great deal of research has been directed towards the rollover problem, few studies have attempted to determine the sensitivity of occupant injury risk to variations in the vehicle (roof strength), crash (kinematic conditions at roof-to-ground contact), and occupant (anthropometry, position and posture) parameters that define the conditions of the crash. A two-part computational study was developed to examine the sensitivity of injury risk to changes in these parameters. The first part of this study, the Crash Parameter Sensitivity Study (CPSS), demonstrated the influence of parameters describing the vehicle and the crash on vehicle response using LS-DYNA finite element (FE) simulations.

More than half of occupant lower extremity (LEX) injuries due to automotive frontal crashes are in the knee-thigh-hip (KTH) complex. To design the injury countermeasures for the occupant LEX, first the biomechanical and injury responses of the occupant LEX components during automotive frontal crashes should be known. The objective of this study is to develop a detailed biofidelic occupant LEX Finite Element (FE) model based on the component surfaces reconstructed from the medical image data of a 50th percentile male volunteer in a sitting posture. Both volumetric (unstructured) and structural mesh methods were used to generate the solid elements (mostly hexahedral type) to enhance the model simulation accuracy. The FE model includes the femur, tibia, fibula, patella, cartilage, ligaments, menisci, patella tendon, flesh, muscle, and skin. The constitutive material models and their corresponding parameters were defined based on literature data.

The advanced Pedestrian Legform Impactor (aPLI) incorporates a number of enhancements for improved lower limb injury prediction capability with respect to its predecessor, the FlexPLI. The aPLI also incorporates a simplified upper body part (SUBP), connected to the lower limb via a mechanical hip joint, that expands the impactor’s applicability to evaluate pedestrian’s lower limb injury risk also in high-bumper cars.As the aPLI has been developed to be used in standardized testing, further considerations on the impactor’s manufacturability, robustness, durability, usability, and repeatability need to be accounted for.. The aim of this study is to define and verify, by means of numerical analysis, a battery of design modifications that may simplify the manufacturing and use of physical aPLIs, without reducing the impactors’ biofidelity. Eight candidate parameters were investigated in a two-step numerical analysis.

Seat belts for rear passengers are not commonly used, even though they can significantly reduce fatalities. A passenger seat belt reminder (PSBR) is installed in order to encourage seat belt use, but the effectiveness of PSBRs on the rear seat passenger has not yet been proven. We have developed a methodology to assess PSBR effectiveness. There are two pathways to encourage seat belt use. The first is that PSBR directly facilitates the passenger's use. The second is to motivate the driver request passengers to use seat belts. In the experiment, we asked participants sitting in the driver's seat to select one of five ranks of likelihood to encourage the passenger when a PSBR was presented. We also asked participants sitting in the rear passenger seat to select the rank of likelihood to use the belt voluntarily with PSBR and that to use the belt when the driver requested. The degree of likelihood was quantified by averaging the assigned percentage values to the ranks.

Thoracic injuries are one of the main causes of fatalities and severe injuries in car crashes. The tools available today for studying these injuries are not up to par with the latest implementation of restraint systems and airbags. THORAX-FP7 is a collaborative medium scale project under the Seventh Framework. It focuses on the reduction and prevention of thoracic injuries through an improved understanding of the thoracic injury mechanisms and the implementation of this understanding in an updated design for the thorax-shoulder complex of the THOR dummy. The updated dummy should enable the design and evaluation of advanced restraint systems for a wide variety (gender, age and size) of car occupants.