杨明飞 程华瑞 沙志平

摘 要：为了研究强震作用下损伤井架结构的力学演化规律，利用有限元建立某矿山井架结构的数值模型。在模型中，按15%失重率的梯度递增考虑井架立柱的局部損伤。首先对井架模型进行静力和模态分析，静力分析结果表明：随失重率的增加，井架结构损伤处应力和顶层最大位移均增大，并且呈现出二次函数关系;模态分析显示，在所选的失重率范围内，井架结构的局部损伤对其模态频率影响不大。接着对模型进行了强震作用下的动力分析，结果表明：随着地震波峰值加速度的增加，井架顶层最大位移、最大层间位移角和损伤处应力均呈现出线性增长。同时在地震波峰值加速度相同的情况下，失重率对井架结构顶层位移影响显著，和无损井架结构相比，结构顶层最大位移增幅达到76.89%。

关键词：损伤井架结构;强震作用;力学演化;失重率;模态频率;峰值加速度

Abstract：To study the mechanical evolution law of the damaged derrick structure under the strong earthquake action， a numerical modelwas established by using ANSYS software， in which the local damage of the column was considered according to the increase gradient of 15% weight loss rate. Firstly， the static and modal analyses of the derrick model were carried out. The results of static analysis showed that the stress at the damaged region and the maximum displacement at the top layer increased with the increase of the weight loss rate， showing a quadratic function relationship， while the results of modal analysis showed that the local damage in the chosen range of weight loss rate had little effect on its modal frequency in this paper. From the dynamic analysis with the strong earthquake action considered， it was found that the maximum displacement， the maximum interlayer displacement angle and the maximum stress at the damaged region all increased linearly with the increase of the peak acceleration of seismic wave， while the weight loss rate had a significant effect on the top layer displacement of the derrick structure when the peak acceleration value of seismic wave was certain. Compared with the undamaged derrick structure， the maximum top displacement of the damaged derrick structure increased by 76.89%.

Key words：damaged derrick structure; strong earthquake action; mechanical evolution; weight loss rate; modal frequency; peak acceleration

井架作为凿井设备的主体结构，其安全对凿井工程至关重要。在长期的服役过程中，结构材料经过腐蚀介质的侵蚀，在表面逐渐出现局部锈蚀现象，这对结构的力学性能会产生不利影响。近年，国内外诸多学者对钢材腐蚀展开了大量研究[1-6] 。文献[7-8]研究了经锈蚀处理钢材后力学性能的退化，发现锈蚀率对钢材屈服强度有显著变化，锈蚀率越高，钢材强度退化越明显。文献[9]研究了在潮湿环境下，不同锈蚀位置和锈蚀时间等参数对钢管力学性能的影响，并根据试验结果，拟合出钢管在锈蚀状态下的极限承载力计算式。……