<正>对毛竹（Phyllostachys edulis）、麻竹（Dendrocalamus latiflorus）和绿竹（Dendrocalamopsis oldhami）及箭竹（Bambusa arundinacea）等4种竹材进行了顺纹（轴向）和横纹（径向）抗压动态破坏过程试验，分析了竹材的纵、横向抗压力学性能，并对不同品种不同年龄的竹种抗压强度进行了比较.结果表明：竹材的抗压本构关系、动态破坏过程以及试样的宏观断口形貌间表现出限好的相关性。并且竹材的品种、年龄和抗压方向对竹材的抗压强度都有影响。

In this paper, the control of a semi-active suspension system using a quarter-car vehicle model was investigated. Due to the presence of nonlinear such as a hardening spring, a magnetorheological damper force in a real suspension system, it is very difficult to achieve desired performances using linear control techniques. To ensure robustness, a Variable Structure Model-following (VSMF) controller has been designed. The controller utilized an optimal control scheme for an active suspension as a reference model. In the controller, the parameters of the switching surface are determined using the method of pole assignment. A rate exponent approach was used to obtain the control law. The efficecy of the scheme was investigated through computer simulation.