(A) study on the development of shell strip by non-periodic B-spline finite strip method and application to bridge analysis

Abstract

In this dissertation, stress resultant shell strips with 6 DOF per node using the non-periodic B-spline finite strip method(FSM) are developed. In order to analyze the composite bridge model using the developed shell strips, shell strip elements are incorporated with linkage element for the shear stud of composite bridge, and are employed in the orthotropic formulation of the stiffened plates. Also, shell analysis of prestressed concrete box girder is performed using the non-periodic B-spline finite strip method. The spline finite strip method(FSM) is very efficient for the analysis of bridges with constant geometrical properties, such as the box girder bridges. In the spline FSM, the displacement filed is constructed by using cubic(B3)-spline interpolation in the longitudinal direction and standard polynomial interpolation in the transverse direction. On the other hand, negative moment exists at the supports of the multi-span girder due to the reaction acting to the bearing. If the conventional finite element method is employed for the analysis of multi-span bridge, finer meshes should be used at the interior support. But, the non-periodic B-spline FSM which have shape function modified to express peak value at the support can provide more accurate solution at the supports. Since this FSM can be used to analyze the structures without any finer meshes, this method is very advantageous in the regions that the first derivative of stresses is discontinuous. In this study, the new spline FSM is proposed by the non-periodic B-spline function. The non-periodic B3-splines satisfy the Kronecker delta properties at the boundary and dose not require any tangential vectors at both ends for the description of shell geometry. Therefore, use of the non-periodic B3-splines might be very useful than that of periodic B3-spines. In this study, shell strips are developed by selectively reduced and assumed strain method, and simultaneously each formulation is presented. Firstly...