基于电测法的水轮发电机组上机架应力特性分析

Stress Characteristics Analysis of Upper Bracket of Hydroelectric Generating Set Based on Electrical Measuring Method

为了解立式悬垂式水轮发电机组上机架的应力情况,以耿达水电站3G(#3水轮发电机组)为例,在拟定的典型工况下,运用电阻应变测量法(电测法)测试了上机架的力学性能。结果表明,3G上机架靠近中心体的两条对称的支腿腹板的应力变化梯度较大;应力集中主要发生在上机架支腿肋板拐点;3G上机架最大应力为64.606 MPa,安全系数为3.6,符合脆性材料的强度要求。

To understand the upper bracket stress situation of vertical suspension-type hydroelectric generating set, taking the 8G （the No. 3 unit） of Gengda hydropower station as art example, the mechanical properties of the upper bracket at the typical operating condition was tested by using the measurement of resistance strain. The results show that the change of the stress has greater gradient, which comes two symmetric shaft leg plate of the 3G upper bracket near the centrosome; the stress concentration appears in the corner of the shaft leg plate of upper bracket, and the maximum value reaches 64. 606 MPa, the safety coefficient is 3.6, which meets the strength requirements of the brittle material.