Having considered the main characteristics of stranded wire helical spring machining tool,a novel NC system is proposed to control the precise forming process.

The geometric equations were put forward on a single-wire in the stranded wire helical springs based on the winding relationship between the center curve of the wire and of the springs,the differential equations of curvature and torsion etc.

Based on the forming principle of stranded wires helical spring and the current problems in the manufacturing process,a new design scheme for the number control machine is put forward.

Forces applied to the multi-wire helical compression spring with multi-centre-wires are analyzed,and its axial deflection formulae are derived taking into cons-ideration the effect of contact pressure between the wires.

3-D plastic dynamic analysis of steel frames based on multi-spring model;

The theory about establishing element matrix with multi-spring model is introduced.

Considering the plastic stiff influence of plastic-region shear deformation,paper derives the element stiffness matrix based on multi-spring model and provides element basis for whole frame structure plastic dynamic analysis.

Rigidity modeling of multi-layer leaf spring in electromagnetic vibratory feeder;