Determination of vibroacoustical behavior of plates by intensity methods

İnalpolat, Murat
In this study, sound radiation and power flow characteristics of plates which constitute the bodies of common engineering applications like cars and household appliances are investigated. Three different vibro-acoustical measurement techniques are used in an integrated manner and results obtained are compared with those obtained from analytical models developed. Two-microphone sound intensity measurement with a probe utilizing side-by-side configuration is used to analyze the near-field radiation characteristics of a square steel plate excited by a shaker at its midpoint. Surface intensity is simultaneously measured on the plate with another probe consisting of a condenser microphone and an eddy-current non-contact displacement transducer to compare the results with those obtained from two-microphone sound intensity measurement. Surface intensity is also measured with a probe consisting of a condenser microphone and an accelerometer as an alternative configuration. Structural intensity is used to identify the power flow patterns on the plate. All measurements are repeated for externally damped configuration of the same plate and results are analyzed. Easily adoptable two distinct, lumped parameter models of the plate are developed to compute the sound power radiated by the structure. In these models, the plate is modeled by employing the pulsating sphere and vibrating piston as the elementary source types, alternatively. In the model employing vibrating piston in the baffle, results are obtained with and without mutual interaction among partitions. Results obtained from these models are compared with the experimental results. Error analysis is also conducted for all of the measurement techniques employed.


Analysis of heat treatment effect on springback in v-bending
Sarıkaya, Onur Turgay; Darendeliler, Haluk; Department of Mechanical Engineering (2008)
Aluminum based alloys have wide area of usage in automotive and defense industry and bending processes are frequently applied during production. One of the most important design criteria of bending processes is springback, which can be basically defined as elastic recovery of the part during unloading. To overcome this problem, heat treatment is generally applied to the workpiece material to refine tensile properties. In this study, the effect of heat treatment on springback characteristics of aluminum stud...
Analysis of high frequency behavior of plate and beam structures by statistical energy analysis method
Yılmazel, Canan; Ünlüsoy, Yavuz Samim; Department of Mechanical Engineering (2004)
Statistical Energy Analysis (SEA) is one of the methods in literature to estimate high frequency vibrations. The inputs required for the SEA power balance equations are damping and coupling loss factors, input powers to the subsystems. In this study, the coupling loss factors are derived for two and three plates joined with a stiffener system. Simple formulas given in the literature for coupling loss factors of basic junctions are not used and the factors are calculated from the expressions derived in this ...
Mixed-mode fracture analysis of orthotropic functionally graded materials
Sarıkaya, Duygu; Dağ, Serkan; Department of Mechanical Engineering (2005)
Functionally graded materials processed by the thermal spray techniques such as electron beam physical vapor deposition and plasma spray forming are known to have an orthotropic structure with reduced mechanical properties. Debonding related failures in these types of material systems occur due to embedded cracks that are perpendicular to the direction of the material property gradation. These cracks are inherently under mixed-mode loading and fracture analysis requires the extraction of the modes I and II ...
Investigation of wear behavior of aged and non-aged SiC-reinforced AlSi7Mg2 metal matrix composites in dry sliding conditions
ÇELİK, YAHYA HIŞMAN; Demir, Mehmet Emin; KILIÇKAP, EROL; Kalkanlı, Ali (Springer Science and Business Media LLC, 2020-01-01)
Metal matrix composites (MMCs) with their splendid mechanical properties have been specifically designed for use in fields such as aerospace and aviation. The presence of hard ceramic particles in MMC increases the hardness of the matrix product and decreases its coefficient of friction. Therefore, the wear resistance is improved. Moreover, the mechanical properties of these composite materials can be improved by applying heat treatments. In this study, AlSi7Mg2 MMCs with 15 wt% SiC reinforcement were produ...
An electronic control unit design for a miniature jet engine
Polat, Cuma; Dölen, Melik; Department of Mechanical Engineering (2010)
Gas turbines are widely used as power sources in many industrial and transportation applications. This kind of engine is the most preferred prime movers in aircrafts, power plants and some marine vehicles. They have different configurations according to their mechanical constructions such as turbo-prop, turbo-shaft, turbojet, etc. These engines have different efficiencies and specifications and some advantages and disadvantages compared to Otto-Cycle engines. In this thesis, a small turbojet engine is inves...
Citation Formats
M. İnalpolat, “Determination of vibroacoustical behavior of plates by intensity methods,” M.S. - Master of Science, Middle East Technical University, 2004.