Papers by Keyword: Crashworthiness

Abstract: The principles of fuselage design for crashworthiness are analyzed based on investigating the theory of energy and momentum to the impact of an aircraft’s crash on occupants in order to increase the chance of survival for occupants. It indicates that minimizing the amount of bumped soil leads to the reduction of resistance from soil to the aircraft while crashing along the y-axis direction (horizontal) and increasing the energy absorption improves the crashworthiness of the aircraft along the z-axis direction (vertical). The deformation of the aircraft cabin and the acceleration of the occupants during a crash are the two most important factors to consider for crashworthiness. The improved fuselage design for crashworthiness is proposed for both y-axis and z-axis directions. Suggestions for the crashworthy fuselage design are given in order to obtain high performance of crashworthiness design, which is meaningful to the future design for fuselage’s crashworthiness.

Abstract: In order to identify the crashworthiness of neotype flexible safety fence, methods was created by conducting FEA (finite element analysis) computer simulation and full-scale impact test based on the current available evaluation standard. Above all, the model of “vehicle-guardrail” was set up based on virtual proving ground (VPG) pretreatment software, the safety in the impact between vehicle and neotype flexible safety fence were studied from the aspects of the moving locus of vehicle, the acceleration of vehicle and the maximum lateral displacement of guardrail etc. Secondly, full-scale impact test was conducted for the guidance quality of guardrail to the tested vehicle. The test results indicated that the neotype flexible safety fence was inconspicuous to the tested-car, which was basically the same to the simulation results, and the evaluation parameter of guardrail met the acceptance criteria.

Abstract: In order to test and verify the feasibility of the 5 roped new flexible safety fence posted with I-shaped cross section. So the full—scale impact test was studied. Four mainly aspects of the preparation for full—scale impact test study, testing and data collection, testing results and data analysis , conclusion were stated. The results show that the various elements of the new flexible safety fence meet the evaluation criteria, the maximum dynamic deformation is short, and it is no obvious stumbling resistance to the testing vehicles.

Abstract: Buckling and crushing behaviour of hollow structure was studied through experiments and numerical simulation. The experimental material was a thin aluminium square tube (38 x 38, 1.2 mm thick). Quasi-static crushing load was applied using a Universal Testing Machine, Shimadzu Autograph (AG-X) series which uses TRAPEZIUMX software for control and data logging. Finite element simulation of the crushing test was done using LS-DYNA software. Results of the two analyses were compared and found in good agreement. The study provides an insight on ways to increasing energy absorption of light weight aluminium tubes. The simulation procedure can be used for further investigation of aluminium tubes of different cross section areas and geometries.

Abstract: The drivers were hurt seriously by the vehicle steering column in the frontal collision. So a steering column with well energy-absorbing is very useful for the drivers. In this paper, the crashworthiness of a vehicle steering column is investigated by using the explicit dynamics finite element analysis method. Based on the proposed finite element model, the steering column with different material parameters including elastic modulus and yield strength are analyzed. Moreover, the displacement, velocity and energy absorption is discussed. The simulation results show that the crashworthiness of the vehicle steering column is significantly influenced by the yield strength. However, the elastic modulus has little effect on the crashworthiness.

Abstract: Expansion tube energy absorber is of interest in bumper device on the spacecraft, for example the seat-bumper and its crushing characteristics have shown an excellent performance. This paper contributes to the analysis and investigation of the crushing characteristics of the expansion tube energy absorber, by simulating the response of the 2Al2T4 expansion tube subjected to quasi-static axial compressive loading, using the LS-DYNA finite element code. Corresponding tests were conducted to serve as comparison purpose. Satisfactory level of agreement between simulation and testing results was obtained regarding the main characteristics of the tested expansion tubes such as peak compressive load, energy absorption and the overall compressive response. Formula of the crushing force deduced using plastic mechanic theory was checked. Impact model was also constructed and dynamic simulations were performed to investigate the axial impact response of the expansion tube energy absorber. The simulation results of quasi-static and dynamic compression response of the expansion tube are very similar.

Abstract: The front bumper inner plate was researched based on contrastive analysis of the crashworthiness considering using 22MnB5, a typical hot forming AHSS (Advanced High Strength Steel) and DP590, a kind of general high strength steel. In this paper, we contrasted energy absorption, section force, and maximum displacement of the two different front bumper systems in low-speed collision. The analysis shows the front bumper inner plate using hot forming AHSS can improve the crashworthiness of automobiles and make it more balanced and reasonable to transfer collision energy and force. As a result, the maximum displacement of the front bumper system decreases and other parts such as front side rails can be safer. Thus, using hot forming AHSS in designing a front bumper inner plate can improve the passive safety of automobiles.

Abstract: This paper mainly uses nonlinear finite element software ANSYS/LS-DYNA to simulate the impact response of the sandwiched polyurethane composite steel tube as well as the traditional steel pipe. Comparative numerical simulation experiments were carried out in which sandwiched polyurethane tube and steel tube with the same mass were respectively collided with rigid balls in the same velocity. The paper mainly analyzes the maximum collision force, absorbing energy and the maximum collision depth of the rigid collision ball of the two different types of tube. Then it concludes that the sandwiched polyurethane composite pipe crashworthiness of the collision is better than that of the traditional steel tube.

Abstract: In this paper, a certain B737 aircraft fuselage section was used to research the influence of different impact conditions on fuselage dynamic characteristics. A finite element model of fuselage was built up from FS380 to FS500. The impact responses of fuselage subjected to 9.133m/s vertical velocity were analyzed under the conditions of 0° roll angle, 10° left roll angle and combination acceleration. The differences of transformation and acceleration history curves under different conditions were compared. The research results show that the performances of 10° left roll angle will change fuselage transformation and acceleration of seats location, the appears of combination acceleration will increase transformation of floor and decrease acceleration at the seats location. The crashworthiness of aircraft structure can be effectively improved by selecting the appropriate landing way.

Abstract: This paper presents impact behaviour and energy absorption response of car door safety beams. Low carbon steel of thickness 2.25 mm, designed into four different shapes of, tube-beam, I-beam and II-beam were used in this experiment to study the effect of impact load on the crash characteristic of the door beams in terms of load bearing and attenuation of energy. The tube-beam is the conventional beam commonly used in cars today. The reason propelling the investigation of other beams is to draw a parallel comparison with the conventional tube beam and possibly obtain an optimised design in terms of impact absorption capability. Masses of impactors used in the impact load simulations were 10 kg, 20 kg, 30 kg, 40 kg and 50 kg at an impact speed of 30 km/h. Analysis were carried out on all samples focusing on energy absorption and deformation characteristics of the beam structures using Pam Crash^TM finite element analysis software. Results from this studies indicated that the II-beam design is better than the other beams in terms of the energy absorption and deformation. The proposed II-beam design may be able to prolong the useful life of passenger car door.