Effect of Local Heating on the Mechanical Characteristics of Repaired Automotive Panels

Flame straightening is a technology process used to eliminate deformations. This method relies on local heating of the material to correct geometry or damaged parts. In the local automobile services its main use is for repairs of less critical deformed components. The maximum temperature and thermal gradient, heating time, cooling rate and number of heating cycles affect the mechanical properties since local heating can alter material microstructure. The aim of this research was to determine the mechanical characteristics of thin steel plates repaired by local heating associated with plastic deformation (similar to hot working) and cold straightening (similar to local cold working) for automotive side and door panels made of structural steel. Thin sheet plates, 0.9mm thickness, were deformed by impact and repaired by local heating using the flame and induction heating then plastically deformed while hot as well as straightened without heating. The heat repaired samples were studied by light microscopy to determine microstructure change and samples were tensile tested to determine their mechanical characteristics. Local excessive grain growth generates anisotropy, the assembly behaves as a composite material with regions that show significant plastic deformations while others little or no deformations at al. Without procedures adjusted to each material repairs involving heating are to be avoided, cold working should be employed when replacement is not possible.

Impact Resistance and Shore Hardness of Barkcloth Reinforced Epoxy Composites for Interior Automotive Panels

The global impact of the consequences of climate change due to an increase in Green House Gas (GHG) emissions are visible. With the implementation of EU directives on waste and end of life disposal strategies, there has been a surge of activity driven by the European automotive industry to introduce Natural Fiber Composites as a substitute to synthetic composites, where appropriate. This paper therefore reports the impact and shore hardness of composites reinforced with a naturally occurring non-woven fabric barkcloth. The composites were produced using a layering architecture; the impact properties show that samples with layering sequence I and IV had the best sequence for the impact properties. The shore hardness of the composites was 72 which is presentable. This further confirms the potential of barkcloth reinforced composites for interior automotive panels.

Study on Modular Design of Trimming Die Structure for Automotive Panels

This paper describes an automated design system for trimming die structure. Considering the complexity of trimming dies, a modular design method was used to define module’s functions and determine the design processes of trimming dies. Through analyzing the relationship of structure and function of trimming dies, the systematic analysis of modularization for trimming dies is achieved from assembly-level division. By using parametric design method, the internal connection between modules is analysis from part-level division, and the module-based design process of complex part is accomplished. The CAD system for trimming dies is developed on platform of UGNX software. The application results show the high efficiency and design flexibility.