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The importance of on-site, in-depth accident research studies has been recognized internationally especially in developed countries. In order to address problems related to road safety, it is important to understand the epidemiology and causation of crashes. For this an in-depth investigation of the crash site, vehicles involved and injury details is required. Detailed crash information helps in analysing the events leading to crash and developing safety measures and/or intervention to reduce crashes. In order to pilot such an activity in India, an in-depth accident data collection activity had been carried out on national highway connecting Delhi to Jaipur (NH-8) for a duration of over a year by a joint team of IIT-Delhi and NATRiP. A total of 1220 road traffic accidents (RTA) notifications were received by the team, of which 186 cases were attended and detailed data was collected in a pre-decided format.

Many research groups are developing Human Body FE Models (FE-HBM) as a tool to be used in safety research. The FE-HBM's currently available are in certain fixed postures. Repositioning of model in alternate postures is needed for use in out of position (OOP) occupant simulations and different pedestrian posture simulations. Postural change in upper extremity can be split two processes, viz, repositioning of spinal vertebra and repositioning of the soft tissue associated with the spine. The objective of this study is to establish a methodology to regenerate pelvis flesh with change in spine/pelvis position. The outer profile of the pelvis flesh should ideally be parametrically described with respect to the associated hard tissues which is not the case in existing FE-HBM's. The affine invariant (Farin, 1990) property of cubic Bezier curves is used in this study.

Finite Element simulation of a lower extremity model is used to (1) determine which of the muscle parameters maximum force capacity (Fmax), initial activation levels (Na) and maximum muscle contraction velocity (Vmax) affect ligament strains the most and (2) to identify which muscles affect the knee response the most in low speed, just below the knee, lateral impact. Simulations have been performed with Fmax, Na and Vmax varying from their reference values. Sensitivity of ligament strains to variation in muscle parameters has been studied. It is observed that knee response is more sensitive to Fmax and Na than Vmax. Amongst the muscles varied, reduction in the Fmax and the Na in the hamstring and the gastrocnemius muscles affects the knee ligament strains the most. The hamstring parameters significantly affects the ACL, the PCL as well as the MCL strains whereas, change in the gastrocnemius parameters affects only the MCL strain.

In a significant number of automobile crashes involving pedestrians, the ligaments which control the stability of the knee, often get severely loaded. In lateral impact on knee during automotive crashes, varus-valgus motion results in failure of ligament by avulsion or by rupture in the middle region It is known that properties vary in different regions of the ligament. Experimental measurement of tensile load-elongation behavior of the middle region of bovine medial collateral ligament at strain rates of 10−4 /s to 160/s are reported here. The results show that the stress-strain behavior is linear under quasi-static loading whereas it is nonlinear and strain rate sensitive in dynamic loading conditions.

This study aims to develop a methodology to generate anatomically correct postures of existing human body finite element models while maintaining their mesh quality. This repositioning is often done by running dynamic simulations. Such simulations, while taking a lot of time have the disadvantage of giving distorted elements as well as require a lot of expertise and have subjective interventions. Also, the anatomical correctness of the final position, and the kinematics followed during repositioning by dynamic simulations are uncertain. The developed method is based on computer graphics techniques and repositions a joint in just a few seconds. Repositioning of the lower extremity was also carried out using Finite Element (FE) simulations and analysed. The repositioning results from the two techniques were compared and it was found that the technique based on computer graphics gave satisfactory results.

In vehicle-pedestrian collisions, lower extremities of pedestrians are frequently impacted by the vehicle front structure. The aim of the current study is to understand the role of muscle activity in knee joint injuries at low velocity lateral impacts, characteristic of vehicle-pedestrian collisions. Therefore, a group of muscles in the lower extremity are modeled using bar elements with the Hill material model. The reflex response of the muscle is then included. Simulations indicate that muscle activation decreases the probability of failure in knee ligaments.

The objective of this study is to establish a methodology to identify the dynamic properties of soft tissues. Nineteen in vitro impact tests are performed on human muscles at three average strain rates ranging from 136/s to 262/s. Muscle tissues are compressed uniaxially up to 50% strain level. Subsequently, finite element simulations replicating the experimental conditions are executed using the PAM-CRASH™, explicit finite element solver. The material properties of the muscles, modelled as linear isotropic viscoelastic material, are identified using inverse finite element mapping of test data using Taguchi methods. Engineering stress - engineering strain curves from experimental data and finite element models are computed and compared during identification of material properties at the above mentioned strain rates. Response of finite element models, with extracted material properties, falls within experimental corridors indicating the validation of the methodology adopted.

An analysis of the rollover propensity of a make of a TSR used extensively in S.E. Asia roads is presented using a 6-degree of freedom simulation. Verification of the model was against measured accelerations measured over speed breakers. Rollover stability was analyzed through simulating Increasing Steer, NHTSA J Turn, and Road Edge Recovery maneuvers.