Slip Damping Mechanism in Welded Structures Using Response Surface Methodology

Response surface methodology (RSM) is a technique used to determine and represent the cause and effect of relationship between true mean responses and input control variables influencing the responses as an n-dimensional hyper surface. Welded joints are used extensively in many modern industries to fabricate jointed structures that contribute significantly to the inherent slip damping. The main problem faced in the manufacture of such structures is the selection of optimum combination of input variables for achieving the required damping. This problem can be solved by developing the mathematical models through effective and strategic planning and executing experiments by RSM. This investigation highlights the use of RSM by designing a four-factor three-level central composite rotatable design matrix with full replication of planning, conducting, executing and developing the mathematical models. This is useful for predicting the mechanism of interfacial slip damping in layered and welded structures. The design utilizes the initial amplitude of excitation, number of tack welded joints and surface roughness at the interfaces as well as the material property to develop a model for the logarithmic damping decrement of layered and welded structures with different end conditions. Experimental results indicate that the proposed mathematical models adequately predict the logarithmic damping decrement within the limits of the factors that are being investigated.