| 1. |
- Chen, X., et al.
(författare)
-
Optimization of longitudinal beam for improvement of crashworthiness in frontal and offset impacts
- 2012
-
Ingår i: 2012 3rd International Conference on Digital Manufacturing and Automation, ICDMA 2012. Guilin, Guangxi, 31 July - 2 August 2012. - 9780769547725 ; , s. 582-585
-
Konferensbidrag (refereegranskat)abstract
- The aim of the study is to optimize the longitudinal beam based on 100% overlapping rigid barrier ( 100% RB ) impact and 40% overlapping offset deformable barrier ( 40% ODB ) impact. The 100%RB and 40%ODB impact FE models were developed in LS-DYNA and validated by using results from crash tests. According to the requirement of crashworthiness, the peak of acceleration of left B-pillar and energy absorbed per unit mass of longitudinal beam were chosen as optimization objects, and the thicknesses of four parts of the longitudinal beam were considered as the design variables. Furthermore, uniform design was applied to build variable samples. Optimal results were obtained by surrogate model built by Kriging and optimization method NSGA-II (Non-Dominated Sorting in Genetic Algorithms-II). The results showed that 100%RB and 40%ODB impact should be considered together when longitudinal beam was designed. The optimized longitudinal beam matches well and effectively improves vehicle crashworthiness.
|
|
| 2. |
- Guo, Q., et al.
(författare)
-
A study on protecting of the far side occupants based on road traffic accident reconstruction
- 2012
-
Ingår i: 2012 3rd International Conference on Digital Manufacturing and Automation, ICDMA 2012. Guilin, Guangxi, 31 July - 2 August 2012. - 9780769547725 ; , s. 140-143
-
Konferensbidrag (refereegranskat)abstract
- A study on injuries of far side passenger in vehicle side impact was carried out by using a real road accident. Firstly, the trace of the accident car was reproduced using PC-Crash code. The impact velocity of the passenger car calculated from PC-Crash was used as the input data for MADYMO modeling of occupant kinematics. Then the dynamic responses of the occupants were analyzed using the calculated injury parameters of the driver. Furthermore, LS-DYNA code was used to simulate the impact between the head of the driver and the left shoulder of the occupant. In the end, a MADYMO model with an airbag between driver and occupant was developed, and the protective efficiency of the airbag was showed by comparing the models with and without airbag.
|
|
| 3. |
- Guo, W., et al.
(författare)
-
Effects of bull bars on head and lower extremity injuries in vehicle-pedestrian collision
- 2012
-
Ingår i: 2012 3rd International Conference on Digital Manufacturing and Automation, ICDMA 2012. Guilin, Guangxi, 31 July - 2 August 2012. - 9780769547725 ; , s. 356-359
-
Konferensbidrag (refereegranskat)abstract
- This study aimed to investigate the effect of bull bar on injuries of pedestrian head and lower extremities based on accident reconstructions and parameters analysis. Four real-world accidents with detailed information were reconstructed via simplified vehicle-pedestrian collision models (two of which with bull bars) in MADYMO. The injury mechanisms of pedestrians caused by bull bar were analyzed, comparing with non-bull-bar vehicle. Moreover, a pedestrian-friendly bull bar was proposed considering the influence of structures of bull bars on pedestrian injuries. The results of accidents reconstructions indicated that the rigid bull bar caused high risk of injuries on lower extremities. The design parameters, such as the height and leading length of upper bull bar had remarkable influences on the injury severity of head.
|
|
| 4. |
- He, P., et al.
(författare)
-
A study on rear seat occupant injuries in side impact
- 2012
-
Ingår i: 2012 3rd International Conference on Digital Manufacturing and Automation, ICDMA 2012. Guilin, Guangxi, 31 July - 2 August 2012. - 9780769547725 ; , s. 144-147
-
Konferensbidrag (refereegranskat)abstract
- This paper described a study on the dynamic responses and injury risk of rear seat occupant in side impact. A PSM (Prescribed Structure Motion) model was created based on a passenger car model, which consists of car side structures, a SID-Ils dummy and rear seat in MADYMO environment. The structural responses of the vehicle body were obtained from the FE simulation of side impact. The kinematics of the vehicle body were imported into MADYMO PSM model as loading condition, consequently the kinematic responses of the dummy were acquired from the PSM simulation. It was noticed that the rear seat occupant subjected to a serious head injury, but pelvis force was much smaller than the specified value in C-NCAP (2012). A parametric study was implemented in three impact locations and two impact angles to investigate the risk of head injury. The results show that the head of rear occupant was most likely to be injured in side impact, and the HIC values were large under different form impact In addition, the HIC values of dummy head varied slightly with the different impact positions and angles. Therefore, it is representative that the HIC level of the rear dummy was analyzed through the simulation according to requirement in C-NCAP.
|
|
| 5. |
- Jiang, K., et al.
(författare)
-
Optimization of bumper system for pedestrian lower leg protection from vehicle impact
- 2012
-
Ingår i: 2012 3rd International Conference on Digital Manufacturing and Automation, ICDMA 2012. Guilin, Guangxi, 31 July - 2 August 2012. - 9780769547725 ; , s. 578-581
-
Konferensbidrag (refereegranskat)abstract
- This paper aimed at improving a bumper system to meet the second phase EEVC (European Enhanced Vehicle Safety Committee) requirements for pedestrian lower leg protection. An approach is presented to optimize the front bumper system for minimizing the risk of pedestrian's lower leg injuries from the bumper impact. Firstly, a vehicle FE model was developed, a two-layer-material EA (Energy Absorber) and a lower stiffener were also developed to attach in the front bumper system. Then some structure parameters of the EA and the lower stiffener were selected and the design of experiment with orthogonal arrays was used to generate the test sample points. Finally, the multi-objective optimization of the structure parameters was conducted based on the NSGA-II (Non-dominated Sorting Algorithm). The maximum tibia acceleration, the maximum knee bending angle and the maximum shear displacement were chosen as the objective functions. The optimized results were used to redevelop the EA and the lower stiffener FE modals. The results of the study show that the performance of the vehicle for lower leg protection could be dramatically improved by the optimization of EA and lower stiffener and the second phase EEVC requirements for pedestrian lower leg protection can be satisfied.
|
|
| 6. |
- Kong, C., et al.
(författare)
-
A study on pedestrian detection models based on real accident data from IVAC database in Changsha of China
- 2012
-
Ingår i: 2012 3rd International Conference on Digital Manufacturing and Automation, ICDMA 2012. Guilin, Guangxi, 31 July - 2 August 2012. - 9780769547725 ; , s. 136-139
-
Konferensbidrag (refereegranskat)abstract
- This study aims to evaluate the probabilities of pedestrian detection within the response time of vehicle collision avoidance system of a car. For this purpose, the carpedestrian accident scenarios were analyzed using selected data from the IVAC accident database, in which the cases were collected from in depth investigations of the accidents in Changsha of China. The selection criteria were: (1) the accident occurred between 2001 and 2008; (2) the accident involved a passenger car, SUV, MPV or pick-up truck; (3) the pedestrian was not standing still before impact. Based on these criteria, 389 car-pedestrian cases were selected. The two most common scenarios (F1 and F2) were identified as the pedestrian crossing a straight road from the left (F1) or the right (F2) of the drivers. A mathematical model was developed with the frontal impact cases of F1 or F2 scenario. The following four parameters describing the configuration before the accident were studied: the trajectory and speed for both the car and the pedestrian. Considering the different half detective angles of the sensor system (15 degree, 30 degree, 45 degree), the probabilities of pedestrian detection were calculated. It was found that when the half detective angle was equal or larger than 30 degrees the sensor system could detect more than 94% of the pedestrians in both evaluated scenarios.
|
|
| 7. |
- Li, G., et al.
(författare)
-
Influence of vehicle front structure on compatibility of passenger car-to-SUV frontal crash
- 2012
-
Ingår i: 2012 3rd International Conference on Digital Manufacturing and Automation, ICDMA 2012. Guilin, Guangxi, 31 July - 2 August 2012. - 9780769547725 ; , s. 492-495
-
Konferensbidrag (refereegranskat)abstract
- Front structure of vehicle is one of the major factors which influence compatibility in vehicle-to-vehicle frontal crash. However, the influence of vehicle front structure with different overlap ratios has not well studied yet. Based on the simulation results of a small car to an SUV frontal crash, the compatibility was investigated in terms of the vehicle frontal stiffness and geometry height with different overlap ratios. The amount of the intrusion of the small car was chosen as the parameter for evaluating compatibility performance. Simulation of vehicle-to-vehicle crash in conditions of different stiffness, geometry height and overlap ratio were developed by using LS-DYNA. From the simulation results, it can be found that the influences of the frontal stiffness and geometry height on the compatibility are discrepant at different overlap ratios. The compatibility performance of the two vehicles could be improved by controlling the front stiffness and geometry height reasonably.
|
|
| 8. |
- Peng, Yong, et al.
(författare)
-
Modeling and validation of windscreen laminated glass behavior during fracture
- 2012
-
Ingår i: 2012 3rd International Conference on Digital Manufacturing and Automation, ICDMA 2012. Guilin, Guangxi, 31 July - 2 August 2012. - 9780769547725 ; , s. 541-544
-
Konferensbidrag (refereegranskat)abstract
- The objective of the study is to provide a method to simulate the mechanical behavior of windscreen laminated glass. The polyvinyl butyral (PVB) laminated glass is manufactured by pressing a layer of PVB film in between two pieces of glass plates under the high temperature condition. In this study, windscreen models are developed using different combination of glass and PVB with various connection types and two mesh sizes (5mm & 10mm). Then each windscreen model was impacted with standard adult headform under LS-DYNA environment and the results were compared with the experimental data reported in the literature. The results show that the behavior of windscreen developed with double layered shell elements of glass and PVB each with tied element connection simulates best the test results. Furthermore, the influence of fracture stress of glass on the above mentioned windscreen was investigated. It was observed that the area of crack and the peak value of headform acceleration are determined by the critical fracture stress and 50MPa fracture stress of glass best predicts the headform acceleration level and the cracks of windscreen.
|
|
| 9. |
- Sun, J., et al.
(författare)
-
Optimization of thorax-pelvic airbag for occupant safety in vehicle side impact
- 2012
-
Ingår i: 2012 3rd International Conference on Digital Manufacturing and Automation, ICDMA 2012. Guilin, Guangxi, 31 July - 2 August 2012. - 9780769547725 ; , s. 586-589
-
Konferensbidrag (refereegranskat)abstract
- Based on the C-NCAP side impact test results and component tests of a type of car, two typical type of pelvic-thorax airbag sub-models was developed using MADYMO and LS-DYNA software. They are single-chamber airbag with one inflator and dual-chamber airbag with two inflators. Based on the analysis of parameters of the single-chamber airbag, the factors that influence the dual-chamber airbag are determined. The protection performance of those side airbags were investigated using orthogonal experiment design (OED) and comprehensive equilibrium methods. The models with better performance were found and factors that influence the two different side airbag were determined. The injury of the dummy decreased dramatically in side impact and met the C-NCAP requirement.
|
|
| 10. |
- Sun, N., et al.
(författare)
-
A comparative study on biofidelity between TRL and LSTC legform impactor
- 2012
-
Ingår i: 2012 3rd International Conference on Digital Manufacturing and Automation, ICDMA 2012. Guilin, Guangxi, 31 July - 2 August 2012. - 9780769547725 ; , s. 21-24
-
Konferensbidrag (refereegranskat)abstract
- The purpose of this paper is to compare the biofidelity of LSTC and TRL legform impactor. A finite element model of simplified front vehicle structure was established. The simulation tests were conducted by using this simplified car model against two different legform impactors and a FE lower extremity, respectively at a speed of 40km/h. The simulation results from the two legform impactors were compare with that of the FE lower extremity. The compared outputs include tibia acceleration, shear displacement, knee bending angle. The test results show that the tibia acceleration of the impactors and the FE lower extremity are approximately consistent. As to the shear displacement and the knee bending angle, though the output of the impactors are not agreed so well with that of the FE lower extremity, the trend are comparable to some extent. The results of the FE lower extremity are higher than that of the legform impactors. The results of LSTC impactor has a better agreement with that from FE lower extremity.
|
|
