Present research deals with the classical coupled thermoelasticity response of an annular disk subjected to thermal shock. Disk is made of an isotropic homogeneous material. The governing equations for the classical coupled thermoelasticity in polar coordinates are obtained and rewritten in a dimensionless form. Unlike many other available works, where the energy equations in linearized, in the present work the nonlinearity due to temperature change is kept. The obtained governing equations are discreted via the generalized differential quadrature method and traced in time using the Newmark time marching scheme. Results are provided to explore the differences between the thermally nonlinear and thermally linear formulations.
thermally nonlinear; generalized differential quadrature; classical coupled thermoelasticity;
newmark time marching method
J. Kiani, M. Safari: Chaharmahal va Bakhtiari Power Distribution Company, Sharekord, Iran
Y. Kiani: Faculty of Engineering, Shahrekord University, Shahrekord, Iran
Passenger-car to pedestrian accidents usually involves much information of traces left on road or vehicle body, which may be used to reconstruct the accidents. The wrap-around distance (WAD) represents the contact position among pedestrian´s head and vehicle body. In order to make full use of this vehiclepedestrian contact characteristic to analyze the impact speed of vehicle, this paper discusses the correlation between the WAD and the impact speed of vehicle. Passenger-car to pedestrian accidents are investigated to obtain the real contact characteristics. Based on body parameters of Chinese people, a finite element model is built to simulate the collision involving pedestrian and passenger-car and further explore the relationship between the WAD and vehicle impact speed. Meanwhile, the different braking deceleration of vehicle, height of vehicle front part and walking speed of pedestrian are considered as independent variables, respectively. The results reveal that the relationship between the WAD and impact speed of vehicle under these different conditions. The impact speed of vehicle has approximately linear relation with the WAD, which could be applied for vehicle speed estimation when the traces on the road surface and braking operation of driver are uncertain. This research suggests a new method for vehicle speed analysis and accident reconstruction. Two real-world accident cases are employed to verify this new method for vehicle speed determination.
pedestrian-vehicle accidents; vehicle impact speed, wrap-around distance (WAD); finite element simulation; accident reconstruction
State Key Laboratory of Automotive Safety and Energy, Tsinghua University, Beijing 100084, China