The bottom flange buckling happened at the bottom flange near the connection regardless of simply supported connection or rigid connection.

Based on the proposed model with known temperature distributions,the bending angle induced by the laser can be calculated.

Special incline is not usually main function plane of pressing, its external shape size and bending angle are not dimensioned directly in 2D part drawing;the data needs calculating.

In the experiment it has been found that: when the thickness and length of the sheet metal is invariable, the bending angle increases with the sheet width increasing, and it tends to a fixed value when the sheet width is large enough.

This paper analyses the influence factors of a critical bending angle of cold bend structural steel under the influence of modulus of elasticity, legged length, and waisted width and thickness of the plate, limits of strength and elasticity.

The effects of process parameters(laser power,scanning velocity,number of scannings) and work piece geometry(specimen width) on the bending angle were investigated,then the experimental phenomenon was analyzed.

By using Monte-Carlo method,defining two dimensionless quantities including relative mean value deviation factor and variation factor,the variability of calculation results for bending angles is researched,in the conditions of the geometric parameters,material thermophysical properties parameters and laser machining parameters occurring stochastic variability.