拉压不同模量凹腔陶瓷导流块动力固有模态特性研究

Dynamic Natural Mode Characteristics Analysis ofCavity Ceramic Diversion Block with DifferentModulus in Tension and Compression

关键词:  双模量  动力特性  陶瓷导流块  二次开发  固有频率  振型  材料属性分布图

Key words:  Bi-modulus  Dynamic characteristic  Ceramic diversion block  Secondary development  Natural frequency  Vibration mode  Material property distribution diagram

摘要:

为了研究拉压不同模量(以下简称双模量)凹腔陶瓷导流块的动力特性，将陶瓷导流块等效成一根双模量材料简支Euler梁，从而得出凹腔火焰稳定器在双模量材料下的振动情况，保证该结构在高温状态下稳定。以双模量简支Euler梁为研究对象，通过二次开发，实现了Ansys平台分析具有该类材料属性结构动力特性的功能。将得到的前三阶固有频率与文献中推得的频率计算公式所得的固有频率进行了分析对比，得到的误差除了第一阶外都大于5%，发现文献所得结果有缺陷。将得到的各阶频率及振型曲线与已知的经典弹性理论的频率与振型曲线进行对比，说明材料的双模量属性对固有频率的影响很大，对振型曲线并没有影响。通过振型及材料属性分布图能直观地观察到材料的拉压区域，说明材料的拉压区域不能仅分为两个区域，振型阶次越高分区也越复杂。

Abstract:

In order to study the dynamic characteristics of the ceramic diversion block with different modules in tension and compression (the following is referred as bi-modulus)， the ceramic diversion block was equivalent to a simply supported Euler beam with bi-modulus， thus， the vibration of the cavity flame stabilizer with bi-modulus material was obtained to ensure that the structure is stable at high temperature. Taking simply supported Euler beam as a research project， the function of analyzing dynamic characteristics of materials which have these material properties has come true in Ansys by secondary development. After comparing the initial three frequencies which were gained from finite element method and the analytical formula in a literature respectively， errors were gained. Except for the first-order frequency， errors are all more than 5%， so the analytical formula in literature has some flaws. Comparing the frequency and vibration mode curve of each order with these which were gained in classical elastic theory， it shows that the bi-modulus property of material has a great influence on the natural frequency and has no effect on the vibration mode curve. The tensile and compressive zones of the material can be visually observed through the vibration mode curves and material property distribution diagrams， indicating that the zones of tension and compression of the material cannot be divided into only two. The higher the vibration mode， the more complex the zone is.