Method for predicting bending durability of electric wire and bend protection member, and apparatus and recording medium storing program therefor

A bending durability prediction method of predicting a bending durability of a plurality of wires laid at a predetermined bend, and of a bend protection member attached at the bend to protect the plurality of wires by using an infinite element method, the bending durability prediction method comprising:

• a storing step of previously storing stress tables which represent minimum stresses according to which it is assumed that the plurality of wires and the bend protection member will be damaged;
• a setup step of setting up the plurality of wires, the bend protection member, an atmosphere temperature, pre-bending initial shapes for the wires and the bend protection member and final bent shapes for the wires and the bend protection member;
• an infinite element model preparation step of preparing infinite element models for the plurality of wires and the bend protection member;
• a stress calculation step of calculating stress, for each of infinite elements of the infinite element models, produced by bending the infinite elements from the initial shape to the final bent shape;
• a maximum stress search step of searching, among the stresses obtained at the stress calculation step, for the maximum stress for each of the plurality of wires and the bend protection member;
• a stress table reading step of reading stress tables corresponding to the plurality of wires, the bend protection member and the atmosphere temperature designated in the setup step;
• a damaged member specifying step of specifying the wire or the bend protection member that is first damaged, while referring to the stress tables that are read at the stress table reading step and the individual maximum stresses that are found at the maximum stress search step for the wires and the bend protection member;
• and
• an output step of outputting information specifying the wire or the bend protection member that is first damaged.

A bending durability prediction apparatus for predicting a bending durability of a plurality of wires laid at a predetermined bend, and of a bend protection member attached at the bend to protect the plurality of wires by using an infinite element method, the apparatus comprising:

• a setup unit for setting up the plurality of wires, the bend protection member, an atmosphere temperature, pre-bending initial shapes for the wires and the bend protection member and final bent shapes for the wires and the bend protection member;
• an infinite element model preparation unit for preparing infinite element models for the plurality of wires and the bend protection member;
• a stress calculation unit for calculating stress, for each of infinite elements of the infinite element models, produced by bending the infinite elements from the initial shape to the final bent shape;
• a maximum stress search unit for searching, among the stresses obtained by the stress calculation unit, for the maximum stress for each of the plurality of wires and the bend protection member;
• a prediction function acquisition unit for obtaining prediction functions for the wires, the bend protection member and the atmosphere temperature designated by the setup unit;
• a predicting unit for referring to the prediction functions obtained by the prediction function acquisition unit, obtaining numbers of bendings for endurance which correspond to the maximum stresses for the wires and the bend protection member, and identifying the smallest number of bendings for endurance;
• and
• an output unit for outputting the smallest number of bendings obtained by the predicting unit.

A computer readable recording medium storing a program for predicting a bending durability of a plurality of wires laid at a predetermined bend, and of a bend protection member attached at the bend to protect the plurality of wires by using an infinite element method, the program causing a computer to function as:

• a setup unit for setting up the plurality of wires, the bend protection member, an atmosphere temperature, pre-bending initial shapes for the wires and the bend protection member and final bent shapes for the wires and the bend protection member;
• an infinite element model preparation unit for preparing infinite element models for the plurality of wires and the bend protection member;
• a stress calculation unit for calculating stress, for each of infinite elements of the infinite element models, produced by bending the infinite elements from the initial shape to the final bent shape;
• a maximum stress search unit for searching, among the stresses obtained by the stress calculation unit, for the maximum stress for each of the plurality of wires and the bend protection member;
• a prediction function acquisition unit for obtaining prediction functions for the wires, the bend protection member and the atmosphere temperature designated by the setup unit;
• a predicting unit for referring to the prediction functions obtained by the prediction function acquisition unit, obtaining numbers of bendings for endurance which correspond to the maximum stresses for the wires and the bend protection member, and identifying the smallest number of bendings for endurance;
• and
• an output unit for outputting the smallest number of bendings obtained by the predicting unit.