Papers by Keyword: Crashworthiness

Abstract:

This paper presents numerically the empty tube response subjected to oblique loading. According to literature survey, there have large number of works discuss on the crushing performance when subjected to axial loading. However, lack of work available on the crushing behaviour under oblique loading. Therefore, this work presents the numerical studies on the crushing behavior of empty tube subjected to oblique loading. ANSYS Finite element program was used to model and solve the problem. The developed model was firstly validated with the previous result and it is found that the results obtained were acceptable. There were two important parameters were used such as tube geometry and oblique loading. According to the present results, when oblique angles were increased, the crushing performance decreased. However, when the elliptical ratios were increased, the energy capabilities increased.

Abstract: This present paper describes numerically the tube responses subjected to eccentric loading using ANSYS finite element program. According to literature review, tremendous amount of works available on discussing the axial crushing of empty tube under axial loading. However, lack of work related with the crashworthiness aspect of tube crushing under eccentric loading was identified. Therefore, the eccentric compressive loading on the empty tubes were focused. There have important parameters were studied such as the eccentric loading. According to the present result, the behaviour of crashworthiness expected to increase when the increment of eccentric loading was introduced. The crashworthiness behaviour and energy absorption capabilities demonstrated efficiently by the collected data mean crushing force and peak crashing force.

Abstract: Improving the crashworthiness of ship is an important guarantee for ship security. To fill different materials in the shipboard structure or attach fender devices outside the shipboard are important measures that can improve the crashworthiness of ship. They are boiled down to the use of crashworthiness materials, and the impact of crashworthiness materials on the double side ship is classified as the changes of shipboard structure elastic modulus, and then this paper carries out an analysis of the impact of the changes of various parts’ elastic modulus of the shipboard structure on the crashworthiness of ship, and the computing result shows that to lay crashworthiness materials on the sheet metal can improve the structure crashworthiness before the rupture occurs, some useful conclusions about the material impact on the crashworthiness of ship are obtained.

Abstract: The objective of this study was to determine the energy absorption of basalt filament wound rectangular tubes under crushing test. Basalt fibre gained a lot of potential in various application due to low cost of this material together with its capability to breaking the domination of e-glass as a reinforcement material. Coupon tensile and axial compression (crushing) test were performed to investigate the strength and energy absorption performance of basalt filament wound rectangular tubes. Both test have been conducted using [±70⁰]₃ winding angle of sample configuration and comparison have been made in coupon test in which the basalt sample shows 8.7% higher than e-glass while produced opposite results in modulus of elasticity. Crushing test was performed in 25mm displacement with different loading rate which are 5, 10 and 15mm/min. The results obtained from three different conditions were compared showing a higher energy absorbed in the lower loading rate. The comparable crashworthiness of basalt suggest possible applications such as automotive industry which is requires a good energy absorb materials in some particular components.

Abstract: In this paper, an analytical prediction and numerical simulation of the behavior of square crash box structures having hole at corners on dynamic axial crushing are studied. The focus of the present theoretical prediction is to calculate the mean crushing force and maximum crushing force during the folding process subjected to axial impact loading. Then, the effect of hole size to the crushing response of square crash box structures was also evaluated. For validation, an explicit non-linear commercial finite element code LS-DYNA was used to predict the response of the structures subjected to axial crushing. It was found that results of numerical method and theoretical prediction were in good agreement. The results showed that, by inserting holes at corners, the folding can be controlled to be always started from the hole, and peak crush load on the first fold can be reduced significantly. Meanwhile, the decreasing of mean crushing force is insignificant compared to the one without holes. Hence, the characteristic of impact energy absorption in a progressive buckling can be improved, the damage in passenger compartment can be minimized, and the deceleration level can be kept in safe level to prevent injury of the passenger.

Abstract: Pole Side Impact Test is one out of three crash tests described by Euro NCAP standard for star rating of a vehicle and is required for assessing the Adult Occupant Protection. In this paper the goal is to determine the crashworthiness of side doors and B pillar in a Pole Side Impact Test based on Euro New Car Assessment Program (Euro-NCAP) using computer and simulation method. In this matter, a vehicle model has been prepared and meshed using Hypermesh and CATIA. The velocity of 29 km/h has been assigned to the vehicle which was on top of a cart while the pole has been assigned as a rigid static object based on Euro NCAP requirements specifically. Results show that different amounts of energy will be absorbed by each part, such as the side doors and the B pillar, and each part has a different effect on the crashworthiness of the vehicle in a Pole Side Impact Test. It can be concluded that to increase the amount of absorbed energy in a Pole Side Impact Test, the part which has more influence should be taken into greater consideration.

Abstract: To assess a car under the Euro New Car Assessment Program (Euro-NCAP), Adult Occupant Protection is one out of three parameters which need to be calculated with a weight factor of 50% while the other parameters, Child Occupant Protection and Pedestrian Occupant Protection, have a weight factor of 20%. The Pole Side Impact Test, beside two other tests, Side & Front Impact, is also required to calculate the Adult Occupant Protection. It shows how important the Pole Side Impact Test is and what an effective role it has in the car rating assessment. In this paper, the objective is to evaluate the effect of thickness on the energy absorbed by the side doors and the B pillar and its crashworthiness in a Pole Side Impact Test based on the Euro NCAP. In this matter, a vehicle model has been designed and prepared using CATIA and meshed using Hypermesh. Five thicknesses have been chosen including 0.6 mm, 1 mm, 1.2 mm, 1.4 mm and the original thickness of the side doors, 0.75 mm. The simulations have been repeated, using LS DYNA solver, assigning each of five thicknesses to the side doors and the B pillar of the vehicle. Initial conditions defined by the Euro NCAP, including velocity and directions, have been applied to the model. A total of 5 simulations have been conducted. The results showed that changing the thickness of the side doors and the B pillar does not necessarily have a direct influence on energy absorbed. The conclusion is that there are different proper thicknesses for each part which will result in optimized energy absorption.

Abstract: In this paper the objective is to study the effect of the material and thickness of the side doors and B pillar on crashworthiness and the energy absorbed in order to select a proper material and an optimized thickness to approach a five star car concept based on the Euro New Car Assessment Program (Euro-NCAP) testing Pole Side Impact. In this matter, four materials and five thicknesses have been chosen for the vehicle model and a total of twenty simulations have been conducted. The results showed that the best selected materials and thicknesses were high strength Steel 204M with a thickness of 1.2mm for side doors and 0.65mm for the B pillar, however, it is important to note that this selection is to maximize the absorbed energy not necessarily to reduce the total weight of the vehicle.

Abstract: Side impact crash test simulates a road crash wherein the side of a vehicle is being impacted, either perpendicularly or at an angle, by the front-end of another vehicle of about similar mass. In Malaysia, this crash configuration is the second leading cause of fatality and injury in road crashes after frontal collision. Extensive research have been carried out worldwide in order to mitigate occupant injury in side impact collision through provision of side impact protection system in vehicle such as side impact airbags and side door bars. As a result, various global regulations and consumer test requirements concerning side impacts have been established to evaluate the effectiveness of the said protection system. Recently, the Malaysian government has implemented the United Nation’s regulation pertaining to side impact protection (UN Regulation 95) for new passenger vehicles in the country. Hence, as a newly established automobile safety rating programme in the region, the ASEAN New Car Assessment Programme (ASEAN NCAP) has a plan in the pipeline to implement UN R95 side impact crash test tentatively in its future assessment scheme. A mobile deformable barrier (MDB) was developed as a preparation towards implementing the ASEAN NCAP’s side impact crashworthiness evaluation. This paper describes characteristics and requirements of the UN R95 as well as the development of the MDB according to the regulation. Several tests and improvements were conducted to ensure the MDB is reliable and having high repeatability for testing.

Abstract: During circulation the railway vehicle is subjected to the action of dynamic forces under the effect of shocks that appear in the driving system caused by stick slip phenomenon, dynamic forces arising from the rolling process when the wheelset is passing over accidental vertical unevenness of the track and also longitudinal dynamic forces occurring in the case of buffering, respectively those caused by frontal impact (the crash forces). The present paper presents the mechanical and mathematical models which are underlying the evaluation of the magnitude of these forces as well as their effects on the resistance of supporting structure of the vehicle and on traffic safety.