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One of the primary concern during assessment of structural integrity of vehicle bodies is the quality of joints used therein. The increased trend in vehicle weight reduction (through use of thin sheet panels) calls for more critical evaluation of the quality of such joints. The electric Resistance Spot Welding (RSW) is one of the largely used joining process for vehicle body structure. Besides the quality of sheet metal, the quality of RSW joints is largely governed by the process parameters e.g. weld current, hold time, squeeze time etc. The quality of RSW joints for durability can be assessed by mechanical strength and fatigue life. The paper presents a methodology for durability assessment of such joints using laboratory specimens and arriving at optimum values of process parameters to maximise the fatigue life. The methodology presented makes extensive use of Design of Experiment (DOE) techniques for better reliability of the results.

There are many aspects of engineering integrity which require careful consideration during design, manufacture, operation and maintenance of the complex systems such as automobile. The ultimate realisation of the “goals of design” implies successful service during the entire life of the product. There is tremendous pressure to utilise lighter materials which results in fuel saving. Assessing the engineering integrity of components and systems under service conditions can be extremely complex and prognostic situation at design stage is often more difficult than the diagnostic one once failure has occurred. Review of various advanced techniques with case studies have been done for the safety and reliability of automobiles for Indian conditions.