根据波动理论，用Timoshenko梁理论在高频范围内分析能量的耗散，通过重建作为频率函数的色散关系曲线，得到动力粘弹性模量及材料的损失因子。根据动力系统的固有特征方程与材料弹性特性的关系，研究利用阻尼损耗因子定量描述在高频情况下，波在结构中传播时的能量耗散效应以及结构阻尼损耗因子的表示方法，并通过实验利用波的色散关系估计结构的动力粘弹性模量，理论分析和实验结果表明了这种方法的可行性。

在对汽车纵向动力学控制系统分析的基础上, 探讨了基于两车的车列纵向自动跟踪的控制问题，建立了二阶车间纵向相对距离控制模型，并设计了汽车发动机/制动器的逻辑切换规律。应用参数自整定模糊-PID 控制，对PID 的三个参数进行调节，控制被控车与导航车的车间纵向相对距离和纵向相对速度误差的变化范围，以达到汽车纵向控制的目的。仿真结果表明：这种方法与模糊控制相比，减少了系统的超调量，增强了动态抗干扰能力，具有一定的鲁棒性，较好地解决了快速性和小超调之间的矛盾。

考虑磁流变减振器阻尼力和悬架弹性元件非线性特性，建立车辆6 自由度的半主动悬架非线性动力学模型。提出了一种基于模糊神经网络系统结构的模型参考自适应控制方法来研究汽车半主动悬架的非线性控制问题，并考虑半车模型前后悬架的输入时滞，对其进行了仿真研究。研究结果表明：运用模糊神经网络非线性控制方法能够使人体和车身垂直加速度、俯仰角加速度都得到很大的衰减，证实这种模糊神经网络控制方法可大大减少路面对车身的振动冲击，提高汽车行驶平顺性。

In this paper, a gear-pair system involving backlash and time-dependent mesh stiffness is examined analytically in an effort to explain the complex behavior of this system. Firstly, the nonlinear dynamic model of a gear-pair system with a periodically time-varying stiffness function and a symmetric backlash is considered. According to this dynamic model, an approximate harmonic solution is obtained which yields mathematical conditions for the occurrence of non-linear behavior in the system response. The stability of the periodic solutions is investigated using Floquet theory. Then the behavior of periodic bifurcation and chaotic motion in the gear-pair system involving backlash and design load is investigated. In some typical parameter regions, the bifurcation diagrams, the chaotic time history and the Poincar

考虑磁流变减振器阻尼力和悬架弹性元件非线性特性，建立车辆半主动悬架非线性动力学模型。应用微分几何非线性控制，经过适当的非线性状态和反馈变换，实现半主动悬架非线性系统的精确线性化，并对系统实施非线性状态反馈控制；根据预定的控制目标及模糊控制策略调节控制参数，设计模糊控制器, 对悬架系统进行了控制仿真研究；利用神经网络模式识别能力对输入数据处理辨别，设计控制网络层，从而达到提高悬架工作性能，改善汽车行驶舒适性的目的。将三种非线性控制方法的仿真结果进行分析比较表明：经模糊控制或神经网络控制后的悬架承受的冲击响应小、振动强度低，比微分几何控制能获得更优异的性能。

对利用人工地震增加采油量的机理作了探讨。研究了振动对含油层的影响，探讨了制约非均匀裂隙多孔介质中渗流的三个基本因素：含油层应力梯度、渗透率和动力粘滞系数，分析了超低频振动对三个基本因素的影响，以及可控震源工作时弹性波的传播特性，并对含油层在振动时的响应特性以及不同震源距的响应作了实验研究。

建立了在高频情况下一维构件的波传播模型，针对工程中常见的螺栓连接梁结构，讨论了波在其中传播的特性及能量耗散问题，提出了一种简化的非线性接头模型。分析与实验结果表明这种非线性模型更能接近实际。波通过梁的螺栓连接时，存在着能量耗散。螺栓松紧程度对能量耗散有较大的影响。在共振频率处，连接部分发生较大的折射。

This paper describes a new approach for non-destructive evaluation and the structural health monitoring with a high frequency impedance-based technique and wave propagation measurement. This new technique utilizes the direct and the converse electromechanical properties of piezoceramic (PZT) patches which are used as actuator-sensors to provided a low-power driven constant voltage dynamic excitation, and to record the modulated current flow through the structure. Elastic wave can be generated in structure by using PZT transducers. Therefore, it relies on tracking the electrical point impedance to identify incipient level damage. The wave may be used to obtain fundamental properties of the structural or to locate flaws. The advantage of this new approach compared with other NDE techniques are discussed. The most advantage of this technique over other NDE techniques is that it can perform continuous monitoring of the structure using non-intrusive small transducer that could be remotely interrogated in an automated mode. In addition, the experimental example is used to show the measurement method and the results.

A dynamic impedance-based structural health monitoring technique is introduced. According to the direct and the converse piezoelectric property of piezoelectric materials, the piezoceramic ( PZT ) can be used as an actuator and a sensor synchronously. If damage like cracks, holes, debonding, or loose connections are presented in the structure, the physical variations of the structure will cause the mechanical impedance modified. On the basis of introducing the principle and the theory, the experiment and the analysis on some damages of the structure are studied by means of the dynamic impedance technique. On the view of experiment, kinds of structural damages are evaluated by the information of dynamic impedance in order to validate the feasibility of the method.

建立了在高频情况下，一维构件的波传播模型，针对工程中常见的螺栓连接梁结构，讨论了波在这种情况中传播的特性及能量耗散问题，提出了一种简化的非线性接头模型。分析与实践结果表明这种非线性模型更能接近实际，波通过梁的螺栓接部时，存在着能量耗散。螺栓松紧程度对能量耗散有较大的影响。在共振频率处，连接部分发生较大的折射。