Design, FE Analysis and Experimental Validation of a Passive Vibration Isolator for Electronic Equipment of a Mobile Vehicle

This paper presents the design strategy of a passive vibration isolator made form combination of elastomers and metal. The objective was to design & develop "Passive vibration isolator" to safeguard the sensitive electronics from vibration transmitted from due to road terrain. These electronics equipment’s were mounted on two racks placed side by side in a customized container, which in turn was fitted on a commercial vehicle. Two types of elastomers (Pure Rubber & Silicon Rubber) were chosen for carrying out the tensile tests to determine the stiffness parameters of these elastomers. Based on test results, elastomer material was chosen & mechanical design was perceived to prepare passive elastomer isolators of two types consisting of single layer and double layers. Mathematical Models were developed for each type of isolators along with electronics boxes. Finite Element Analysis (FEA) was carried out using ANSYS® workbench. In order to verify FEA results and to the effectiveness of both isolators’ types, two mock up electronics boxes were manufactured& integrated with designed single layer as well as double layer isolator. Vibration testing was carried out by employing the loading as per MIL-STD-810G on vertical, longitudinal & transversal directions on the two electronics boxes respectively. Both Finite Element Analysis (FEA) and testing results showed that single layer elastomer (pure rubber) has better isolation as compared to the two-layer elastomer. Later on, the single layered elastomer (pure rubber) passive isolators were manufactured & integrated with electronic units mounted inside mobile vehicle. Experimental data obtained using ISO 10816 Vibration Severity Standard for Vibration Analysis by carrying out the actual road trials of Mobile Vehicle on the intended pathways. The comparison of experimental data with FEA shows that proposed passive vibration isolator fulfills the vibration isolation requirement.