Research Of Crack Control For Concrete Beam Embedded In Sma Based On The Double Spline QR Method

New application prospect appeared for the smart material with the development of smart structures at the end of the1980s. Shape Memory Alloy material has a unique shape memory effect and super elastic properties, so it could produce a greater recovery stress under a certain condition, for what it could be widely used in the crack control and deformation control of structure.This paper considers the discrete way in two directions of x and y based on the simple spline QR method, then works out the double spline QR method to analyze the plane problem. The mechanical property and the influence of holes to the stress and sideway of the shear wall are analyzed by the double spline QR method. Finally, this paper gives two ways to research the control of crack of concrete by SMA. One is the driving force of SMA is equivalent to off-axis force which are axial force and reverse bending moment in effect, then integrated into the formula about crack width in norm, the other is the driving force of SMA is equivalent to a nodal loads, which could be combined with the double spline QR method and deduced to the governing equation of crack width. Based the combines above, the influence of the initial stress, diameter and numbers of SMA to the effect of crack width control is analyzed.This paper gives the calculation procedure programmed by MATLAB, the accuracy and efficiency of the double spline QR method is proved by the examples in which the results are compared with the analytical solution and finite element solution, and then gives some valuable conclusions.