Analysis on shear lag effect in thin-walled box girder with single-box two-cell based on modified warping displacement function
To enhance the theoretical investigation of the shear lag phenomenon in thin-walled box girders with a single-box two-cell configuration,principles governing the division of flange plate widths were established based on the distribution of zero points in the bending shear flow.Consideration was given to the impact of shear deformation on bending curvature,with the introduction of an internal force balance factor.The longitudinal warping function of the flange plates was modified by leveraging the continuity conditions of longitudinal warping displacement distribution.Additionally,the free-state condition of cantilevered flange plate ends was addressed,and the concept of initial shear rotation angle was proposed to explain the phenomenon that the theoretical stress at the end of cantilever plate is higher than the real stress,and to elucidate the influence of initial shear rotation angle on the longitudinal warping function.By utilizing a dimensionless approach,the relationship of the longitudinal warping function of the flange plates was standardized,and a reasonable formulation of the transverse distribution function of longitudinal displacement was derived theoretically.By employing the principle of energy variation,a differential equation governing the shear lag effect in thin-walled box girders with a single-box two-cell configuration was formulated,alongside provision of displacement boundary conditions.An illustrative example involving a fully loaded uniformly distributed load on a simply supported thin-walled box girder with a single-box two-cell configuration was utilized to obtain theoretical solutions using the analytical method proposed herein.Furthermore,a corresponding mechanical model was developed using ABAQUS finite element software to compare and analyze theoretical analytical solutions with finite element numerical results.The findings confirm the rationality and feasibility of determining flange plate width division for the shear lag effect in thin-walled box girders with a single-box two-cell configuration based on zero points in bending shear flow.The theoretical analysis method presented in this study,incorporating considerations of initial shear rotation angle and flange plate stress correction,demonstrates excellent agreement with finite element numerical results for flange plate stress and deflection values,with a maximum error not exceeding 2%.This not only validates the suitability of using the cosine function as the transverse distribution function of longitudinal warping displacements but also verifies the accuracy of the theoretical analysis method and its derivation.
thin-walled box girdersingle-box two-cellshear lag effectzero point of bending shear flowinitial shear rotation angle
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维普
