中文摘要：

为了精确计算双Ⅰ型GFRP-混凝土组合梁的动力特性,首先推导出与其动力特性相关的抗弯刚度、剪切刚度、质量惯性矩、扭转刚度和截面翘曲刚度的等效计算公式;根据达朗贝尔原理,分别按照Euler梁理论、Timoshenko梁理论和薄壁杆件约束扭转理论推导出双Ⅰ型GFRP-混凝土组合梁的弯曲振动频率和扭转振动频率计算公式。选择双Ⅰ型GFRP–混凝土组合模型试验梁,运用等效计算公式所得该类型梁的截面特性值与CUFSM软件计算值吻合良好,验证了等效计算公式的可靠性;采用ANSYS12.0软件建立了试验梁的有限元实体模型,并对ANSYS计算的有限元值、模型试验值及推导公式计算结果进行了对比分析。结果表明,Timoshenko梁理论计算的弯曲自由振动频率与实测值及有限元值吻合良好,扭转频率计算公式所得频率值与实测值吻合良好,所得结论可为GFRP-混凝土组合梁的动力特性计算提供参考。

英文摘要：

In order to calculate the dynamic characteristics of the the two Ⅰ-shaped GFRP-concrete hybrid bridge accurately,the formulas of the flexural stiffness,shear stiffness,the mass moment of inertia,torsional stiffness,warping stiffness are deduced by method of stiffness equivalence. According to D＇ Alembert＇s Principle,The formulas of flexure vibration frequency are deduce based on the Euler beam and Timoshenko beam theories,while the formula of torsion vibration frequency is deduce based on thin-walled structural mechanics theory. We can select the two Ⅰ-shaped GFRP-concrete hybrid beam as the model,The section characteristics obtained by use of the equivalence formulas are in good agreement with the results obtained by the CUFSM software. The finite element solid model of the test beam is established by using ANSYS12. 0 software,and the finite element values of ANSYS,model test values and formula calculation results are compared and analyzed. The result shows,the flexural free vibration frequency calculated by the Timoshenko beam theory has good agreement with the measured values and the finite element values,the frequency values obtained by the torsion frequency formula has good agreement with the measured values,The conclusions can provide a good reference for determining the dynamic characteristics of the two Ⅰ-shaped GFRP-concrete hybrid bridge.