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

项目描述：本项目支持弗吉尼亚州布莱克斯堡弗吉尼亚理工学院和州立大学工程科学与机械系Ali Nayfeh教授与约旦伊尔比德约旦科技大学机械工程系Khaled Asfar博士之间的合作研究项目。他们计划进行实验和理论研究，以研究复合材料结构中高频到低频模式的能量传递机制。负责这种能量传递的机制是独特的，因为它既不是自参数共振，也不是外部组合共振，也不是参数组合共振。研究的组合结构主要是具有不同边界条件的梁和板。在弗吉尼亚理工大学完成的分析和实验工作揭示了由于组合和内部共振以及宽间隔模式之间的相互作用，在多自由度系统中存在这种能量交换。这种能量交换可能会改变系统的行为，导致不良后果。研究各种复合材料参数对能量交换的影响，以改进复合材料的设计过程。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博士对各种能量转移机制的理解做出了重大贡献。在复合结构中的应用是特别有趣的。该项目将加强非线性振动一般领域的思想和专门知识的国际交流，并将加强PI在VPI的研究小组与约旦科技大学之间的联系。该研究将复合材料的研究添加到过去三十年来对均匀材料机械结构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.