大型直线振动筛的疲劳寿命及可靠性分析

Fatigue life and reliability analysis of large linear vibrating screen

运用多轴疲劳分析的临界平面法对大型直线振动筛进行了疲劳寿命数值分析,利用电测法测得相似模型筛疲劳危险节点的动应变,并与仿真结果进行对比,验证分析结果的有效性和精确度。运用应力-强度干涉模型对振动筛的疲劳可靠性进行了预测计算,并分析了表面加工质量对振动筛疲劳可靠性的影响程度。实验验证了数值分析结果的有效性和较高的精确度,结果表明大型直线振动筛整体结构的疲劳寿命能够达到预期设计寿命,但振动筛体的侧板、横梁的局部位置疲劳可靠性较低。

The critical plane approach of multiaxial fatigue analysis was used for calculating the fatigue life of the large linear vibrating screen. The dynamic strain of the critical area was measured using resistance strain gage in order to verify the simulation results. The fatigue reliability was analyzed using the stress-strength interference model and the influence of surface roughness of the structure was analyzed. The experimental results prove the validity and accuracy of the numerical analysis, the fatigue life of the whole structure is sufficient for working life expectation, but the relia- bility of local positions of the beam and sidewall is deficient and need redesign if necessary.