Abstract: Aiming at the problem of lightweight design by laser beam welding for B-pillar, based on the B-pillar manufacturability analysis, the orthogonal test method was used. The safety analysis of the B-pillar under side collision, based on the maximum intrusion volume and intrusion speed in the collision process, the safety comparison analysis was carried out. Under the premise of meeting the five-star standard of side collision, the scheme with the most weight loss was the optimal lightweight design. The profile tolerance, maximum thinning rate, and collision safety of the actual production B-pillar was analyzed. The results indicate that the position of the weld seam is finally selected from the bottom end of 380 mm is optimal. The final material combination is DP800/DP600, and the thickness is 1.8 mm/1.6 mm, the quality of the B-pillar is reduced from 4.449 kg to 3.50 kg, and the weight loss is 21.3%. By adjusting the stamping process parameters, the B-pillar product is tested. The pass rate of the profile is 100%, and the maximum thinning rate is 21.1%, which is in line with the requirements of the OEM. The side impact test shows that the strength meets the requirements and the simulation and experimental results are basically the same, and the error is within 4%, indicating the reliability of the analysis.
Key words: vehicle B-pillars; lightweight; tailor-welded blank; side collision; manufacturability