Abstract:

In order to obtain mechanical behavior and volumetric characteristic of weft knitted fabric, a loop model was built on the improved mass-spring model. The problem that the non-uniform rational B spline curve (NURBS) can not pass through all bonding points was solved by using the interpolation algorithm which can form new bonding points and the points are linked by NURBS. In order to simulate the twist of folded yarn, the NURBS is regarded as the geometric center with four cylinders around. Three relative Euler angles were calculated by the spatial coordinates of adjacent points. The relationship between the variables of the loop and the displacement of the mass was analyzed by measuring the variables of the loop. The displacement of the mass and mechanics equations were calculated by velocity-Verlet numerical integration methods. Based on the Microsoft Visual Studio 2010 integrated development tools and OpenGL 3-D graphics library, 3-D simulation of weft knitted fabrics can be realized visually on the computer screen.

Key words: weft knitted fabric, non-uniform rational B spline curve, mass-spring model, rotation matrix, loop deformity