Abstract
Keywords
FE simulations, Tolerance allocation, Aesthetics, Visualisation, Aesthetics.
Abstract
The latest developments in CAD technologies have provided excellent design tools for designing automotive parts and assemblies according to customers specifications. These have substantially reduced the task of design engineers but have raised users expectations to very high standards. Design engineers are compelled to use a wide range of material from fabric, leather and glass reinforced plastics to aluminium and titanium alloys for reducing weight of parts, increasing their stiffness and strength, achieve better performance, fuel economy and aesthetic requirements of the users. Material properties of all these parts and assemblies are to be considered to predict their deformation behaviour under various manual and automated assembly conditions, which is an extremely difficult task throughout the design phase especially for allocation of tolerances. These parameters are to be achieved at costs acceptable to potential customers in a highly competitive business environment. These requirements have enhanced the need of visualising the influence of tolerances on part deformation for the tolerance design engineers in automotive industry. Finite Element simulation technique has been investigated to observe the influence of tolerance allocation on deformation of simple parts in the past.
Present research is an extension of previous effort and is focused on using FE simulations for allocation of positional tolerances in flexible sheet metal automotive parts using the IDEAS software. Experimental investigations have been conducted using a multi axial test rig andoptical scanning system for deformation measurement. The methodology provides a means of constructing experimental rigs and using FE simulations simultaneously to assess the influence of allocated tolerances on deformation of automotive parts and assemblies of sheet metal parts. It could be extended to other parts that are manufactured by using different multi layered materials in future. The application of this approach at the initial design stage for tolerance allocation would enable tolerance designers to visualise the influence of tolerance allocation on part deformation physically and through computer simulations. It would ultimately result in a substantial reduction of the overall production costs of automotive parts and assemblies and improve upon their aesthetic properties.