8361

7742

كارشناسي ارشد

طراحي كاربردي

اصفهان، دانشگاه صنعتي اصفهان، دانشكده مكانيك

1392

سيزده، 101 ص: مصور، جدول، نمودار

سعيد ضيايي راد

محمود كدخدايي

14/10/92

حسن نحوي، رضا تيكني

مهندسي مكانيك

ID7742

به فارسي و انگليسي: قابل رويت در نسخه ديجيتال

Nonlinear Dynamic Response Analysis and Modeling of Bi Stable Composite Plates Ahmad Firouzian Nejad Email a firouzian@me iut ac ir Date of submission September 22 2013 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Saeed Ziaei Rad Email szrad@cc iut ac ir Abstract Some important advantages of composite materials such as their high weight to strength ratio was the cause of their prevalent use in many industrial cases in past decades Bi stable structures are special kinds of composite structures that their ability to maintain in their stable configurations without any source of energy has made them suitable for morphing structures Consequently having a comprehensive insight into their static and dynamic behavior is of crucial importance A great amount of research were carried out that focused on the thermal and static behavior of these special plates subsequently the main goal of the present study is to determine frequency and dynamic response of 0 90 bi stable composite plates Therefore a specially written MATLAB code based on the Rayleigh Ritz technique is developed to compute statically stable states and minimum static load results in snap through phenomenon for wide variety of temperature gradient ranges In this investigation the mechanical properties of the composite material was considered as functions of temperature Moreover the effect of modeling resin layers and lay up thickness were also considered Afterwards using a simplified one DOF model and also a Rayleigh Ritz model in conjunction with Hamilton principle first natural frequency and dynamic time responses of plate to the linear and harmonic loads with considering the temperature dependency of materials and modeling of resin layers were obtained and the results were in agreement with the results obtained by finite element simulations in ABAQUS software To eliminate the inaccuracies in the results from Rayleigh Ritz method several assumptions for the function of out of plane displacement field were provided and the effect of these proposed functions were evaluated in static and dynamic behavior of the plate Furthermore the concept of using bi stable composite plate as vibration isolator is investigated and compared with that of an equivalent linear model The results showed that the negative stiffness of these structures can expand the bandwidth of a passive vibration isolator and improve performance Keywords Bi stable plates Snap through Dynamic response Natural Frequency Hamilton Principle Rayleigh Ritz technique Finite Element Vibration Isolator PDF created with pdfFactory trial version www pdffactory com

سعيد ضيايي راد

محمود كدخدايي

حسن نحوي، رضا تيكني