US-Jordan Cooperative Research: Nonlinear Energy Exchange Between High-Frequency and Low-Frequency Modes in Composite Structures

0242109 Nayfeh描述：该项目支持弗吉尼亚理工学院和弗吉尼亚州布莱克斯堡州立大学(弗吉尼亚理工学院)工程科学和机械系Ali Nayfeh教授与约旦伊尔比德约旦科技大学机械工程系Khaled Asar博士之间的合作研究项目。他们计划进行实验和理论研究，以研究复合结构中高频到低频模式的能量转移机制。负责这种能量转移的机制是独特的，因为它既不是自参共振，也不是外部组合共振，也不是参数组合共振。被研究的组合结构主要是具有各种边界条件的梁和板。弗吉尼亚理工大学的分析和实验工作揭示了由于组合和内部共振以及大间隔模式之间的相互作用，多自由度系统中的这种能量交换。这种能量交换可能会改变系统的行为，导致不良后果。将研究各种复合材料参数对能量交换的影响，以改进此类材料的设计过程。范围：该项目涉及分析和实验方法，并结合了美国和约旦科学家的互补专业知识。Nayfeh博士对理解各种能量转移机制做出了重大贡献。复合材料结构的应用尤其令人感兴趣。该项目将加强在一般非线性振动领域的思想和专业知识的国际交流，并将加强国际和平研究所研究小组与约旦科技大学之间的联系。这项研究将把复合材料的研究添加到过去三十年来关于均匀材料机械结构中的非线性模态耦合的大量研究中。

0242109 NayfehDescription: This project supports a cooperative research project between Professor Ali Nayfeh, Department of Engineering Sciences and Mechanics, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg, Virginia and Dr. Khaled Asfar, Department of Mechanical Engineering, Jordan University of Science and Technology, Irbid, Jordan. They plan to conduct experimental and theoretical investigations to study the mechanism for the transfer of energy for high-frequency to low-frequency modes in composite structures. The mechanism responsible for this energy transfer is unique as it is neither an autoparametric resonance, nor an external combination resonance, nor a parametric combination resonance. Composite structures to be investigated are mainly beams and plates with various boundary conditions. Analytical and experimental work that was done at Virginia Tech revealed such energy exchange in multi-degree-of-freedom systems due to combination and internal resonances and interaction between widely-spaced modes. Such energy exchange may alter the behavior of the system leading to undesirable consequences. Effects of various composite material parameters on the energy exchange will be studied in order to improve the design process of such materials.Scope: The project involves analytical and experimental approaches, and combines the complementary expertise of the US and Jordanian scientists. Dr. Nayfeh has contributed significantly to the understanding of various energy transfer mechanisms. The application to composite structures is of particular interest. The project would enhance the international exchange of ideas and expertise in the general field of nonlinear vibrations, and would strengthen the ties between the PI's research group at VPI and the Jordan University of Science and Technology. The research will add the study of composite materials to a large volume of research that has been performed in the last three decades on nonlinear modal coupling in mechanical structures of homogeneous materials.