基于能量法刚接支腿门式起重机挠度预测的研究

STUDY ON PREDICTION DEFLECTION AT GIRDER MIDSPAN OF LARGE TONNAGE RIGID CONNECTION LEGS GANTRY CRANE BASED ON ENERGY METHOD

门式起重机承受额定载荷时主梁跨中的下挠值是门式起重机整机试验的最重要检测指标。对于大吨位门式起重机整机实验时,实验砝码现场准备十分困难,甚至无法进行整机实验检验。针对门架结构考虑了支腿弯矩对主梁挠度影响的情况,推导出集中载荷在主梁跨中处作用时的挠曲线方程。通过分别测量三次小载荷在跨中处作用的主梁下挠值,求得门架结构主梁挠曲线方程系数,从而预测大吨位门式起重机额定载荷时主梁的下挠度。三次小载荷实验法为预测大吨位门架结构主梁挠度提供了实用有效的方法。

It is the most important inspection index the deflection value of the gantry crane girder under rated load in the overall test. For large tonnage gantry crane in the overall test, prepared the experimental weight is often very difficult at the site, or even impossible perform test. In the text, it is deduced the girder deflection curve equation under the considering effects of the leg bending moment to the girder deflection When the concentrated load is applied to the position of the girder midspan. The girder deflection values can be obtained under three-small-loads at the girder midspan, and the coefficients of gantry frame girder flexural equation can be obtained. In this way, the deflection of the large tonnage gantry crane is predicted through the data of the three-small-loads method in the test. The three-smalMoads method provides a practical and effective method for the prediction of the girder deflection of large tonnage gantry structure.