Abstract: A computer-implemented simulation method for use in a molding process comprises steps of specifying a simulating domain corresponding to a genuine domain in a mold disposed on a molding machine, wherein the genuine domain has a mold cavity to be filled with a fluid having fibers from the molding machine in order to prepare a molding product; performing a virtual molding to generate a shear rate distribution of the fluid having the fibers in the simulating domain while using a molding condition for the molding machine; and calculating an orientation distribution of the fibers by taking into consideration an anisotropic rotary diffusion effect of the fibers and the shear rate distribution, wherein the anisotropic rotary diffusion effect is determined by taking into consideration a square of a rate-of-deformation tensor.

Abstract: A computer-implemented method and non-transitory computer medium for calculating a shrinkage of a molding product comprises a step of using a computer processor to calculate a molding pressure of a molding fluid in a molding cavity by taking into consideration an increase of a shear viscosity of the molding fluid by a decrease of a shear rate, and a step of calculating the shrinkage of the molding products by taking into consideration a variation of a specific volume of the molding fluid as the molding pressure and a molding temperature decrease.

Abstract: A computer-implemented method and non-transitory computer medium for calculating a shrinkage of a molding product comprises a step of using a computer processor to calculate a molding pressure of a molding fluid in a molding cavity by taking into consideration an increase of a shear viscosity of the molding fluid by a decrease of a shear rate, and a step of calculating the shrinkage of the molding products by taking into consideration a variation of a specific volume of the molding fluid as the molding pressure and a molding temperature decrease.

Abstract: One aspect of the present invention provides a method for determining orientation of fibers in a fluid having polymer chains, characterized in that the determining of the orientation of the fibers is performed by taking into consideration an interaction between the fibers and the fluid, wherein the interaction between the fibers and the fluid comprises changes in configuration of the polymer chain to cause the entanglement or adsorption between the fibers and the polymer chains. Another aspect of the present invention provides a method for determining orientation of fibers in a fluid having polymer chains, the fibers in the fluid including a transitional movement and a rotatory movement, the method being characterized in that the determining of the orientation of the fibers is performed by taking into consideration a steric barrier effect on a rotary movement of the fibers.

Abstract: One aspect of the present invention provides a method for determining orientation of fibers in a fluid having polymer chains, characterized in that the determining of the orientation of the fibers is performed by taking into consideration an interaction between the fibers and the fluid, wherein the interaction between the fibers and the fluid comprises changes in configuration of the polymer chain to cause the entanglement or adsorption between the fibers and the polymer chains. Another aspect of the present invention provides a method for determining orientation of fibers in a fluid having polymer chains, the fibers in the fluid including a transitional movement and a rotatory movement, the method being characterized in that the determining of the orientation of the fibers is performed by taking into consideration a steric barrier effect on a rotary movement of the fibers.