基于均匀化理论的掺杂纤维对混凝土床身动力学性能的影响分析

Analysis on the influence of doped fiber exerted on the dynamic performance of concrete bed based on the homogenization theory

在机床床身的制造中,以树脂混凝土为代表的复合材料是替代传统铸铁的理想材料,但这种材料的动态特性较差,影响了其使用。其中,惮性模量是影响混凝土床身动态特性的关键因素之一,而在树脂混凝土中掺杂纤维是一种改善床身弹性模量的有效方法。为研究不同纤维尺度对混凝土床身动态性能的影响趋势,采用了均匀化解析结合有限元的方法对其进行分析。首先说明了纤维混凝土均匀化的基本原理与方法;然后结合试验数据验证了该方法的可行性;最后分析了不同纤维尺度对混凝土等效弹性模量的影响趋势和床身的动态特性。结果表明,随着高弹性模量纤维含量的增加,纤维混凝土整体弹性模量随之增加,床身动态性能增强;反之,床身动态性能降低。随着纤维长径比的增大,床身弹性模量先增大后逐渐趋于平缓。

In the manufacturing of machine bed, composite materials represented by resin concrete are ideal materials to replacetraditional cast iron. However,they are not widely applied due to their poor dynamic characteristics. Elastic modulus is oneof the key factors which affect the dynamic characteristics of concrete bed,and doping fiber in resin concrete is an effectivemethod to improve the elastic modulus. In order to explore the influence of different fiber scales exerted on the dynamic performanceof concrete bed,the homogenization analysis is conducted and the finite-element method is adopted. Firstly,the basicprinciples of fiber-concrete homogenization are explained. Then,the experimental data is adopted to verify that the method isfeasible. Finally,both the trend of the influence of different fiber scales exerted on the equivalent elastic modulus and the dynamiccharacteristics of concrete bed are analyzed. The results show that with the ever-growing fiber content characterized byhigh elastic modulus,the overall elastic modulus of fiber concrete rises,and the dynamic performance of concrete bed gets better.On the contrary, the dynamic performance gets worse. As the fiber aspect ratio increases, the elastic modulus of concrete bedfirst increases and then gradually becomes gentle.