EXPERIMENTAL INVESTIGATION AND VALIDATION OF NATURAL FREQUENCY OF RECTANGULAR PLATES AND LAP JOINTS

Abstract

This paper deals with experimental investigation and validation of rectangular plates and lap joint using modal analysis. The purpose of the study is to analyze the dynamic behavior of structures like a rectangular plate, bolted lap joint, and single lap epoxy adhesive joint subjected to impact or shock loads using Finite Element Analysis (FEA) and experimental modal analysis. The various factors that affect the response of single rectangular plate, bolted and adhesive joint structures are studied, such as, mode shapes, damping ratio, natural frequencies etc. The purpose of this paper is to deliver effective techniques using software analysis for the calculation of the vibrant reply of single rectangular plate with rectangular plate lap joints and to validate the predictions by experimental modal analysis and FEA. The FEA method is used to validate the mode shapes, natural frequencies, and frequency response roles of the beams. The three different specimens are used which consist of aluminum material. The initial case study is focused on a simple rectangular plate of cantilever beam subjected to impact force. The second case study is focused on bolted lap joint and single lap adhesive joint. The core objective of this work is to determine the natural frequency and mode shape of all three specimens at cantilever beam condition and first to compare the result of all joints with the single rectangular plate and then compare it with experimental modal analysis. In practical application this kind of modal analysis can be used to analyze various structures to find natural frequency & mode shapes such as cantilever bridge, frame of bicycle, automobile product, Industrial robots (manipulator), building structures, heavy machineries and aircraft industry etc.