Vehicle Collision Tests Research Articles

Vehicle running attitude prediction model based on Artificial Neural Network-Parallel Connected (ANN-PL) in the single-vehicle collision

Artificial neural networks have drawn growing attention for their outstanding predictive capability combined with traditional research methods. This paper aims to propose a vehicle running attitude prediction model based on Artificial Neural Network-Parallel Connected (ANN-PL), predicting the longitudinal displacement (Svx) and vertical displacement (Svz) of the vehicle body, the vehicle head-up angle (α), and the overriding risk (Cd). The 3D multibody dynamics model (MBD) of the single-vehicle impact on the rigid wall, namely 3D-MBD-SV, was established and validated by the experimental full-scale vehicle collision test. Based on the reliable 3D-MBD-SV, the design of experiment (DOE) approach was carried out to obtain the datasets for training the ANN-PL. The ANN-PL exhibited excellent computational efficiency and satisfactory prediction accuracy compared to the multibody dynamics and finite element simulation calculation methods. However, the different network hyperparameters of the ANN-PL network are essential to prediction accuracy, considering the number of hidden layers and neurons in this paper. In terms of the variables factor analysis, the change of Mean Square Error (MSE) method (COM) in the ANN-PL was used to explore the relationship between the eleven essential input variables and vehicle running attitude. It was found that the maximum relative contribution in ANN-PL (Svx, Svz, α, Cd) is vehicle body mass (Mc) at 70.65%, impact velocity (Vx) at 43.39%, vertical offset of the vehicle body center mass (CMz) at 30.14%, and primary suspension axle box spring vertical travel (Dpz) at 13.63%, respectively. The outcome of this study is expected to provide a research method to solve the complicated engineering issue by building a new artificial neural network algorithmic framework combined with the multibody dynamics and finite element simulation calculation methods.

Full-Scale Experimental Study of a Reinforced Concrete Bridge Pier under Truck Collision

Recently, vehicle collisions with bridge piers have occurred frequently, which have attracted the attention of researchers. However, as one of the most important research methods, vehicle collision tests for reinforced concrete (RC) bridge piers are limited. The impact responses and damage characteristics of full-scale RC piers have seldom been studied in actual truck collision tests, which hinders further development in this research area. Therefore, a medium-duty truck will be employed to carry out a full-scale crash test on an RC single-column pier 1 m in diameter in this study. The crashing truck had a mass of 7.76 t and a collision speed of 81 km/h. The damage and failure level of the vehicle and RC pier will be examined, and some critical data will be obtained from the test, such as the displacement, velocity, and acceleration time histories of the truck, and the deflection, acceleration, and reinforcement strain time histories of the RC pier. In addition, based on the accelerations of the cargo box and engine, the vehicular impact forces will be derived approximately and discussed. This will provide valuable experimental data for the study of vehicular collisions with RC bridge piers, especially in the calibration and validation of the finite element (FE) models for truck collisions and the impact resistance evaluation of RC bridge piers.

Analysis of Vehicle Collision on an Assembled Anti-Collision Guardrail.

Traffic accidents such as vehicle collisions with bridge guardrails occur frequently. These accidents cause damage to the driver and the vehicle as well as the bridge. A new type of assembled anti-collision guardrail is proposed in this study. LS-DYNA is a nonlinear display dynamic analysis software used to evaluate the safety of a new type of assembled anti-collision guardrail. A specific, numerically analyzed model of vehicle–guardrail collision is established using LS-DYNA. The energy distribution–time curve of the vehicle collision process is obtained. After comparison with measured data from the vehicle collision test, the model of vehicle–guardrail collision is verified as being correct. Based on this, we analyze the process of a vehicle collision on the assembled anti-collision guardrail. The result shows that the assembled anti-collision guardrail proposed in this paper can better change the trajectory of a moving vehicle and can prevent the vehicle from falling off the bridge. From the car body collision results, the assembled anti-collision guardrail for bridges proposed in this paper can reduce vehicle damage and can protect the driver effectively. From the analysis of the main girder stress on the bridge, an anti-collision guardrail installed on an existing bridge will not cause damage to the main girder during a collision. In order to study the influence of the four parameters on the anti-collision effect, we carried out a comparative calculation of multiple working conditions. The results show that the new type of assembled anti-collision guardrail has good protective performance under different working conditions.

Equivalence study involving rail vehicle collision test conditions

In the context of rail vehicle collision tests, which incur high costs and consume substantial time and energy, the equivalence between a single vehicle crashing into a rigid wall and two identical vehicles colliding with each other was studied. Taking the car body as a rigid body, a three-dimensional multi-body dynamic model was built to simulate a single-vehicle impact and a collision between two identical vehicles; the results showed that the condition of a single vehicle crashing into a rigid wall at a speed of [Formula: see text] can be used to replace the condition of one vehicle moving at a speed of v and crashing into an identical vehicle that is stationary. However, the actual collision is a strong nonlinear process, and it is necessary to conduct the equivalent test of the condition of collision. Based on the similarity theory, the scaled equivalent vehicle model is established. Through a series of scaled model tests, the following conclusion is drawn: if one vehicle moving at a speed of vcrashes into another identical vehicle that is stationary, one can equivalently use a single vehicle with a speed of [Formula: see text] (units: m/s) that crashes into a rigid wall. This study provides practical support for the equivalence of vehicle collision test conditions and holds great value for engineering applications.

Consistency of Calculation Results of Two Typical Vehicle Collision Models

In order to study consistency of calculation results of typical vehicle collision models based on the law of momentum conservation, the difference of coordinate systems of two typical models is analyzed. Consistency of two typical models is studied by using empirical formulas based on vehicle collision tests. From the above study, a vehicle collision accident is analyzed by using two typical models. Results show that calculation results of two typical models are identical under reasonable selection of coefficients in these models, thus two typical models are consistent. Study results provide the basis for consistent analysis of similar models.

Simulation analysis of low-speed front-to-rear vehicle impacts for estimating the severity of passenger injury

This paper presents practical application methods of the non-linear continuous-contact-force model developed for analysis of a low-speed collision; this is the most common type of traffic accident which also has a high rate of injury. With simulation analysis, the forces transferred through the tyres and the braking effects can be considered. The experimental data on the dynamic behaviour of the vehicles and a BioRid-II dummy measured for 13 low-speed vehicle collision tests were analysed. The results corresponded relatively well to the simulation analysis on the acceleration pulses and the whiplash-associated injury rate. For the simulation analysis of the whiplash-associated injury risk in relation to the passenger head–neck movements in front-to-rear impacts, the acceleration pulse was interfaced with a dummy-behaviour analysis program and the movements of and the injury risk to the dummies were estimated.

Determination of the collision speed of a vehicle from evaluation of the crush volume using photographs

In accident reconstruction analysis of a collision between modern vehicles which have a three-dimensional frontal shape, classical two-dimensional crush measurement and modelling have apparent limits. In this paper, a new model which can calculate the collision speed from the three-dimensional crush volume estimated using two-dimensional photographic data of the collision crush shape is presented. The equation for the crush volume and the collision speed include the mass of the vehicle, and it is composed as a single equation, disregarding the size of the vehicle. The optimal coefficients were obtained through least-squares curve fitting using National Highway Traffic Safety Administration collision test data, and they were validated through actual vehicle collision tests. Additionally, a photogrammetry method using only photographic data of the collision is suggested for immediate application in reconstruction analysis of an actual accident, which can make the measurement of the crush volume relatively convenient and accurate.

Development of impact simulator and airbag control algorithm for reliable detection of side-impact collisions

Improved passive safety measurement and analyses are required to minimise injuries to passengers in vehicles when a traffic accident arises. A lot of impact tests using the developed impact simulator have been executed to validate the proposals for the specification of new electronic single point-sensing module (ESPS). This paper describes the structure and control of the simulator that includes servomechanism, data acquisition system, sensor interface circuits, and crash recognition algorithm for the side airbag system. The aim of the tests using this equipment is to make the sensor output signals to be equal to those of real vehicle collision tests. Using the simulator, the output signals have been used to define the threshold values that decide the firing or non-firing conditions for the inflators. The results of undertaken tests are to be applicable to the development process of crash recognition algorithm for the side airbag system.

A Bayesian Approach for Analyzing Results of Vehicle Collision Tests

ABSTRACTCertain motor vehicle safety standards stipulate a collision test speed and a set of performance criteria that vehicles must satisfy during or after the collision test. For example, Federal Motor Vehicle Safety Standard 301 requires a 30 mile per hour (mph) barrier collision and specifies a certain maximum allowable limit on the total spillage of fuel. Vehicle designs are required to meet this standard; however, when collision tests are conducted at speeds higher than the standard, vehicles do not always satisfy the performance criteria. This paper develops a mathematical model for estimating the probability of meeting the standard by using a Bayesian framework to incorporate engineering judgment with collision test results. The model is based on the idea that there are random features to a vehicle's ability to meet performance standards in a collision, especially at such elevated speeds. Example calculations are included to illustrate the estimation of the probability of meeting the standard and to compare it with a maximum likelihood approach.