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大跨度空间网架结构健康检测中杆件轴力无损测试方法至关重要。繁杂和不便现场实施的轴力测试已经影响到健康检测的实用性。探索频率法测试杆件轴力影响因素的变化直接关系到该方法的实用性。针对影响频率法测试空间网架结构杆件轴力的因素研究,能使频率法测试结构杆件轴力时可综合考虑各方面因素,得到精确的数据。通过杆件模型试验分别考虑了杆件轴力、杆件长度、截面及边界条件4因素对杆件自身频率的影响,基于梁弯曲振动理论与数值计算对试验结果进行分析。结果表明,杆件长度、截面及边界条件对杆件自身频率影响较大,杆件轴力对杆件频率影响相对较小,但4个因素对杆件频率影响均呈线性变化且影响程度各不同,可以为频率法测试结构杆件频率时提供参考标准。
The method of non-destructive test of shaft axial force in the health examination of long-span space truss structure is very important. Complicated and inconvenient on-site implementation of axial force testing has affected the usefulness of health testing. It is directly related to the practicality of this method to explore the change of the influencing factors of axial force by the frequency method. Aiming at the factors that affect the axial force of space truss structure by frequency method, the frequency method can take all factors into account when testing the axial force of structure bar, and obtain accurate data. The influences of the four factors of the axial force, the length of the rod, the cross section and the boundary conditions on the frequency of the rod are considered respectively through the model test of the rod. The test results are analyzed based on the beam bending vibration theory and the numerical calculation. The results show that the length, cross-section and boundary conditions of the rod have a great influence on the self-frequency of the rod. The axial force of the rod has a relatively small influence on the rod frequency. However, the influence of the four factors on the rod frequency varies linearly Different, it can provide the reference standard for the frequency method to test the structure rod frequency.