NUMERICAL STUDY OF VIBRO-ACOUSTIC RESPONSES OF UN-BAFFLED MULTI-LAYERED COMPOSITE STRUCTURE UNDER VARIOUS END CONDITIONS AND EXPERIMENTAL VALIDATION

Abstract

THIS ARTICLE PRESENTS THE VIBRO-ACOUSTIC MODELING AND ANALYSIS OF UN-BAFFLED LAMINATED COMPOSITE FLAT PANELS SUBJECTED TO HARMONIC POINT LOAD UNDER VARIOUS SUPPORT CONDITIONS. THE FREQUENCY VALUES OF THE PANEL ARE OBTAINED BY USING SIMULATION MODEL THROUGH THE COMMER-CIAL FINITE ELEMENT PACKAGE (ANSYS) VIA BATCH INPUT TECHNIQUE. INITIALLY, THE RATE OF CONVERGENCE OF THE CURRENT SIMULATION RESULTS IS ESTABLISHED BY SOLVING DIFFERENT EXAMPLES UNDER VARIOUS EDGE SUP-PORTS. FURTHER, THE NATURAL FREQUENCIES AND CORRESPONDING MODES ARE COMPUTED AND COMPARED WITH AVAILABLE PUBLISHED AND EXPERIMENTALLY OBTAINED VALUES. THEN, THE MODAL VALUES ARE EXPORTED TO LMS VIRTUAL.LAB ENVIRONMENT FOR THE COMPUTATION OF ACOUSTIC RESPONSES OF THE VIBRATING LAMINATED PLATE STRUCTURE. FURTHER, AN INDIRECT BOUNDARY ELEMENT APPROACH HAS BEEN ADOPTED TO EXTRACT THE COUPLED VIBRO-ACOUSTIC RESPONSES. SUBSEQUENTLY, THE RADIATED SOUND POWER OF THE STRUCTURE AND THE SOUND PRESSURE LEVEL WITHIN THE ACOUSTIC MEDIUM ARE COMPUTED USING THE PRESENT SCHEME AND COMPARED WITH THE PUBLISHED NUMERICAL RESULTS AND IN-HOUSE EXPERIMENTAL DATA, RESPECTIVELY. FINALLY, A COMPREHENSIVE STUDY HAS BEEN PERFORMED TO HIGHLIGHT THE EFFECT OF DIFFERENT STRUCTURAL PARAMETERS (THICKNESS RATIO, ASPECT RATIO, MODULAR RATIO AND LAY-UP SCHEME), SUPPORT CONDITIONS AND THE COMPOSITE PROPERTIES ON THE ACOUSTIC RADIATION RESPONSES OF THE LAMINATED PLATE STRUCTURE.