Optimization of a B-pillar with tailored properties under impact loading

Within the study's scope, the impact performance of a boron steel B-pillar with three different hardness values and six different B-pillar designs with tailored properties was compared in crashworthiness. Impact simulation results were compared in terms of spe-cific energy absorption and peak crushing force values of the B-pillar. “Upper part T500 and lower part O25 heat treated B-pillar” gave the highest specific energy absorption. “Upper part O25 and lower part T25 heat treated B-pillar” resulted in the lowest peak crushing force and gave the second highest specific energy absorption. This pillar was used in optimization studies to maximize specific energy absorption and minimize peak crushing force. The single-objective optimization problem was solved with Adaptive Re-sponse Surface Method and Sequential Quadratic Programming methods. Specific ener-gy absorption value increased by 47.7% from 1.32 to 1.95 kJ/kg compared reference de-sign for both techniques. Multi-objective Genetic Algorithm and Global Response Sur-face Method were utilized to solve the multi-objective optimization problem, and similar Pareto front curves were obtained. For both methods, the optimal B-pillar with max spe-cific energy absorption increased the specific energy absorption by 51.5% from 1.32 to 2.00 kJ/kg compared to the reference design. However, peak crushing force increased 14.9% from 63.7 to 73.2 kN. Optimal B-pillar could be used in the automotive industry.

Keywords:

B-pillar, Boron steel, Crashworthiness, Optimization, Spesific energy absorption (SEA), Peak crushing force (PCF) Tailored property,

PDF

___

[1] Wang D, Dong G, Zhang J, Huang S. Car side structure crash-worthiness in pole and moving deformable barrier side impacts. Tinshhua Sci Technol. 2006;11(6):725–730. DOI: 10.1016/S1007-0214(06)70256-5
[2] Njuguna J. The application of energy absorbing structures on side impact protection systems. IJCAT. 2011;40(4):280–287.
[3] Zhang B, Yang J, Zhong Z. Optimisation of vehicle side interior panels for occupant safety in side impact. Int J Crashworthiness. 2010;15(6):617-623, DOI: 10.1080/13588265.2010.484193.
[4] Pan F, Zhu P, Zhang Y. Metamodel-based lightweight design of B-pillar with TWB structure via support vector regression. Comput. Struct. 2010;88(1-2):36-44. DOI: 10.1016/j.compstruc.2009.07.008.
[5] Yang Z, Peng Q, Yang J. Lightweight design of B-pillar with TRB concept considering crashworthiness, L. O' Conner (Ed.): 2012 Third International Conference on Digital Manufacturing and Au-tomation, Conference Publishing Services, Danvers, USA (2012), pp. 510-513, DOI: 10.1109/ICDMA.2012.121.
[6] Cao L, Yao C, Wu H. Reliability optimal design of B-pillar in side impact, Proc. of the SAE 2016 World Congress and Exhibition, SAE International, United States (2016), DOI: 10.4271/2016-01-1523.
[7] Öztürk İ, Kaya N, Öztürk F. Design of vehicle parts under impact loading using a multi-objective design approach. MP. 2018;60(5):501–509. DOI: 10.3139/120.111174.
[8] Li Q, Wu L, Chen T, Li E, Hu L. Multi-objective optimization de-sign of B-pillar and rocker sub-systems of battery electric vehicle. Struct Multidisc Optim. 2021;64:3999–4023. DOI: 10.1007/s00158-021-03073-0.
[9] George R, Worswick M, Detwiler D, Kang, J. Impact Testing of a Hot-Formed B-Pillar with Tailored Properties - Experiments and Simulation. SAE Int. J. Mater. Manf. 2013;6(2):157-162. DOI:10.4271/2013-01-0608.
[10] Worswick MJ, George R, Bardelcik A, Ten Kortenaar L, Detwiler D. Thermal Processing History and Resulting Impact Response of a Hot-Formed Component with Tailored Properties – Numerical Study. AMM. 2014;566:34–40. DOI: 10.4028/www.scientific.net/amm.566.34.
[11] Tang B, Wu F, Wang Q, Li C, Liu J, Ge H. Numerical and experi-mental study on ductile fracture of quenchable boron steels with different microstructures. Int. J. Lightweight Mater. Manuf. 2020;3(1):55-65. DOI: 10.1016/j.ijlmm.2019.07.001.
[12] Hyperworks 19.0. Radioss Tutorials, Copyright by Altair Engi-neering Inc., 2019.
[13] Qi C, Sun Y, Yang S. A comparative study on empty and foam-filled hybrid material double-hat beams under lateral impact. Thin-Walled Struct. 2018;129:327-341. DOI: 10.1016/j.tws.2018.04.018
[14] Xiao Z, Mo F, Zeng D, Yang C. Experimental and numerical study of hat shaped CFRP structures under quasi-static axial crushing. Compos. Struct. 2020;249.
[15] J. S. Rao, Kumar B. Three-dimensional shape optimization through design of experiments and meta models in crash analysis of auto-mobiles: Proc. of the Symposium on International Automotive Technology 2013, SAE International, India (2013), pp. 1-13, DOI: 10.4271/2013-26-0032.
[16] Wang G G, Dong Z, Aitchison P. Adaptive response surface method- a global optimization scheme for approximation-based de-sign problems. Eng. Optim. 2021;33(6):707-733. DOI: 10.1080/03052150108940940.
[17] Shi L, Yang R-J, Zhu P. An adaptive response surface method for crashworthiness optimization. Eng. Optim. 2013;45(11):1365-1377. DOI: 10.1080/0305215X.2012.734815.