基于健康监测的钢桁加劲梁钢-混组合桥面系竖向温度梯度效应分析

Vertical Temperature Gradient Effect Analysis of Steel-concrete Composite Deck System on Steel Truss Stiffening Girder with Health Monitoring

为实现对钢桁加劲梁钢-混组合桥面系温度效应的精准分析,尝试应用了温度梯度效应的空间有限元计算法,通过算例验证,确定了空间有限元计算法的合理性;基于现行规范,提出了一种竖向温度梯度计算模型。以某大跨度钢桁加劲梁悬索桥为例,对该桥健康监测温度数据进行了分析,建立了竖向温度梯度模型;结合有限元程序及温度梯度模型,进行了空间竖向温度梯度效应研究。结果表明:有限元法计算精度高,适用于大型复杂结构的空间温度效应的分析;提出的钢-混组合桥面系的温度梯度计算模型精度高,且简单适用;钢-混组合桥面系竖向温度梯度效应十分明显,产生的应力不容忽视;该类型的钢-混组合桥面系竖向温度梯度与应力呈线性关系,相同结构的应力线性系数为定值。

In order to realize the precise analysis of temperature effect of steel-concrete composite deck system on steel truss stiffening girder,a 3-D finite element method for temperature gradient effect was adopted to verify the feasibility of the method through case study.Based on current codes,a simplified calculation model for vertical temperature gradient was proposed.A long-span suspension bridge with steel truss stiffening girder was taken as the studying case to analyze thetemperature data through health monitoring,and a vertical temperature gradient model was established.Combining finite element program and temperature gradient model,3-D vertical temperature gradient effect analysis was carried out.The results indicate that finite element method with high precision fits for the temperature effect analysis of multiply redundant structure.The explored vertical temperature gradient calculation model is verified to be precise and practical.Vertical temperature gradient effect on steel-concrete composite bridge deck system is great,and the induced stress can not be ignored.The relationship between vertical temperature gradient and induced stress is linear,and the linear coefficients of stress with the same structure are fixed.