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Resistance spot welding is one of the commonly used structural joining processes in sheet metal structures. This paper presents the study of vibration characteristics of a spot-welded sheet metal coupon with a simple finite element model. The finite element spot weld nugget was modelled with Spider Configuration (SC) using commercial finite element code ABAQUS. Analytically the spot welded sheet metal coupon was modeled as a free–free Euler Bernoulli beam. Comparison was made for both natural frequencies and mode shapes of the first three bending modes between finite element model and analytical model. It was found that the simple finite element model was able to predict the spot weld joint vibration characteristics with a minimum of 0.35% and a maximum of 7.3% error.

The PWRI is a type of passive isolation system which is commonly used as shock and vibration isolation system especially applied in lightweight equipment and electronic devices. The PWRI can provide isolation in all direction. It can be flexible in any direction and in all three planes which depends on its stiffness. An experimental study of the lateral stiffness of Polycal Wire Rope Isolators (PWRI) is presented in this paper. It also studied effect of variations in height and width of PWRI on its static stiffnesses. Suitable experimental setup was designed and manufactured to meet the test conditions. The results show that their elastic stiffnesses for lateral loading conditions are highly influenced by their geometric dimensions. It is found that their compressive stiffness reduced by 56% for an increment of 25% in their height to width ratio. Therefore, the stiffness of PWRI can be fine-tuned by controlling their dimensions according to the requirements of the application.

Wire rope isolator is one of the most effective isolation system that can be used to attenuate the vibration disturbances and shocks during the operation of machineries. This paper presents the results of investigation on static elastic stiffnesses (both in tension and in compression) of Polycal Wire Rope Isolator (PWRI) under quasi-static monotonic loading conditions. It also studied effect of variations in height and width of PWRI on its static stiffnesses. Suitable experimental setup was designed and manufactured to meet the test conditions. The results show that their elastic stiffnesses for both tension and compression loading conditions are highly influenced by their geometric dimensions. It is found that their compressive stiffness reduced by 55% for an increment of 20% in their height to width ratio. Therefore, the stiffness of PWRI can be fine-tuned by controlling their dimensions according to the requirements of the application.

Simple spot weld connection models are desirable in huge and complicated finite element models of automotive body-in-white structures which generally contains thousands of spot weld joints. Hence, in this paper six different individual spot weld joint finite element models simplified in terms of their geometric and constitutive representations were developed including the one that is currently used in automotive industries. The stiffness characteristics of these developed models were compared with the experimental results obtained following a simple strategy to design the welded joint based on the desired mode of nugget pull out failure. It was found that the current spot weld modeling practice in automotive industry under predict the maximum joint strength nearly by 50% for different loading conditions. The computational costs incurred by the developed models in different loading conditions were also compared. Hence, a suitable model for spot welded joints is established which is very simple to develop but relatively cheap in terms of computational costs.