中文摘要：

通过分析能量变分原理求解薄壁箱梁剪力滞效应的基本假设,并结合弹性力学中平面应力问题的几何和物理方程,分析薄壁箱梁各板件应力应变关系中弹性模量的合理取值问题,与已有大多数文献中对弹性模量的取值方式相比,按本文修正后的弹性模量的计算结果,能够更好地反映薄壁箱梁剪力滞翘曲的实际情况。材料泊松比是影响两种取值方式的重要因素。通过简支梁算例,对比常用工程材料的不同泊松比数值表明,采用两种取值方式计算所得的应力差值比的最大值均不超过5%,因而,工程实际中按照不修正的简单方式取值也是可行的。

英文摘要：

Through the analysis the basic assumption of the energy Variation principle solving the shear lag effect in thin walled box beam, and in combination with geometry and physics equation in elastic mechanics to solve plane stress problem, the reasonable approaches to assume the elasticity modulus which is in the stress-strain relationship of each thin-walled box girder plate are studied. Compared with the method to assume the elasticity modulus in most of existing literatures, the corrected calculation results of elasticity modulus in this paper can better reflect the actual situation of thin-walled box beam shear lag considering the warping. The Poisson ratio is an important {actor affecting the two kinds o{ methods to solve elasticity modulus. Through the numerical example of simply supported beam and contrast with different Poisson ratios of the common engineering materials, the maximum stress difference ratio which calculated from two methods is less than 5%. Therefore, the simple value method without correction used in engineering practice is feasible.