This paper proposes a standardized vehicle body repair manual for vehicles with major damage to the rear side members caused by rear-end collisions. The manual is used to refine the vehicles. Typical work involves replacing large traffic accident modes with new members or modifying and aligning existing members. If repairs are made for various reasons, the members should be attached based on the body of a new vehicle. Unlike new vehicle members, the accident vehicle repair process depends heavily on the operator's skilled skills (i.e., the performance, purpose, level, and quality of the body replacement work due to the nature of the vehicle body replacement work). When repairing or replacing a rear side member of a body repair, three methods of operation are applied because the damage and deformation vary depending on the object of the other party, although the degree of damage varies. There is no standardized manual for side member over-hole replacement, partial replacement, or partial modification, since these repair methods vary depending on the operator's thoughts and angle of view. Therefore, customers should use standardized vehicle repair manuals to ensure that their vehicle receives the same repair when damaged. This study is expected to develop a standardized vehicle repair manual to reduce the drop in used market prices after replacement or repair of rear side members at vehicle repair plants.

Cars serve as vehicles for the conveyance of both passengers and cargo. Inevitably, traffic accidents constitute a significant facet of vehicular operation. These accidents manifest in various forms, including frontal, rear-end, and lateral collisions. While the resultant vehicular damages may exhibit similarities, they remain inherently distinct. Owing to the intricate nature of automotive body repairs, simplistic adherence to textbook doctrines proves inadequate. The rectification of damaged vehicle bodies hinges upon the practitioner's experiential acumen. Consequently, discourse pertaining to body repair technology necessitates grounding in empirical data encompassing prevailing industry norms and attendant financial implications. Variability in individualized methodologies can engender substantial temporal and monetary outlays within the domain of automotive bodywork. Moreover, the integration of novel material technologies within vehicular structures mandates a perpetual pursuit of knowledge and empirical inquiry into the domain of vehicle body repair procedures, particularly as applied to emerging materials. Compounding this imperative is the unwavering commitment to preserving the safety paradigm from the vehicle owner's perspective, ensuring that restorative interventions subsequent to accidents do not compromise safety benchmarks.

As the time and cost of body repair can be greatly incurred due to differences in individual technologies, body repair technology should be discussed based on data on general working standards and costs, and as new material technology is applied to the body, continuous learning and experiment on vehicle body repair technology is essential. Since the left and right apron and side members with SPR bonding technology are made of different materials, aluminum and high-strength steel, the restoration of the left and right apron side members should be considered technically, as well as safety and environmental pollution. In this study, we experiment with heterogeneous apron and side members applied with SPR bonding and analyze the results.

The hydro-forming design process of the sub-frame side members was studied using a high strength steel of 440 MPa in tensile strength. In the part design stage of the side member, the cross section analysis and the overall process design of the part shape were done. In the detailed simulation results, the maximum thickness reduction rate due to hydro-forming was predicted to be 13% and this was predicted to be a safe level without cracking. The end curvature was reduced to increase the stiffness of the part to design more secure parts and two types of grooves were added to the cross section and compared. The thickness reduction rates of the narrow and wide were improved by 18.6% and 15.6%, respectively when the narrow and wide grooves were added.

Hydroforming is a forming technology in which a steel tube is fixed in a die and formed to fit a specified design shape by applying hydraulic pressure from inside the tube. In present study, the whole process of sub-frame side member development is presented by tube hydro-forming using steel material. At the part design stage, it requires feasibility study and process design aided by CAE (computer aided design) to confirm hydro-formability in details. Overall possibility of hydro-formable side member parts could be examined by cross sectional analyses. All the components is designed and formability is examined from the point of geometry and thinning. From the simulation results, the maximum thickness reduction rate is 55% after hydroforming. In order to improve this result, the feeding by 30 mm is applied to the both sides of the tube and the thickness reduction can be reduced from this management.

Increasing needs for light weight and high safety in modern automobiles induced the wide application of high strength steels in automotive body structures. The main difficulty in the forming of sheet metal parts with high strength steel is the large amount of springback including sidewall curl and twist in channel shaped member parts. Among these shape defects, twist occurs frequently and requires numerous reworks on the dies compensate the shape deviation. But until now, it seems to be no effective method to reduce the twist in forming processes. In this study, a new forming process to reduce the twist deformation during the forming of automotive structural member was suggested. This method consists of forming and restriking of embosses on the sidewall around the stretch flanging area of the part. and was applied in the forming process design of an automotive front side inner member with high strength steel. To evaluate the effectiveness of the method, springback analysis using Pamstampa™ was done. Through the analysis results, the suggested method proven to be effective in twist reduction of channel shaped parts with stretch flanging area.