Abstract: Diameters and the number of respective wires are inputted, and a diameter of a virtual wire formed by converting a wire bundle to a model through a predetermined arithmetic expression derived from rule of thumb, and based upon this, a flexure life estimating process of the virtual wire is carried out. It is possible to easily estimate the flexure life and also to estimate the flexure life and obtain the results immediately after an application subject and a wire harness to be placed have been designed; thus, it becomes possible to shorten the developing period.

Abstract: A bend-test device for wire harnesses capable of handling a plurality of samples at the same time. The bend-test device includes a fixed frame unit, a hinge unit with a fulcrum axis, and a mobile frame unit connected to the fixed frame unit via the hinge unit in a freely pivotable manner around the fulcrum axis. The fixed frame unit includes fixed-side panels respectively including holder holes, each of which holds a grommet carrying a wire harness. The fixed-side panels are arranged in a parallel relation to each other, and aligned perpendicular to the direction of the fulcrum axis, in a freely mountable and removable manner. Likewise, the mobile frame unit includes mobile-side panels respectively including holder holes, each of which holds another grommet carrying the wire harness. The mobile-side panels are arranged as mentioned above, so that each of the mobile-side panels can be opposed to a corresponding one among the fixed-side panels.

Abstract: The invention provides a method of simulating and estimating the minimum lifetime under repeated bending for a wire harness containing a plurality of electrical cables, by applying a compact and lightly equipped device. To this end, representative electrical cables, contained in the wire harness, are subjected to flexing and stretching until they fail under repeated bending, so that the number of bending cycles is obtained for each representative electrical cable. The minimum lifetime for the wire harness can then be estimated on the basis of the shortest cable lifetime that can be found among all the representative electrical cables tested.

Abstract: Diameters and the number of respective wires are inputted, and a diameter of a virtual wire formed by converting a wire bundle to a model through a predetermined arithmetic expression derived from rule of thumb, and based upon this, a flexure life estimating process of the virtual wire is carried out. It is possible to easily estimate the flexure life and also to estimate the flexure life and obtain the results immediately after an application subject and a wire harness to be placed have been designed; thus, it becomes possible to shorten the developing period.

Abstract: A master curve indicating correlation between a bending life and a distortional change quantity of a wire is previously acquired. The master curve is acquired by repetitively bending a single wire and analyzing (CAE analysis with a computer or the like) a distortional change quantity (&Dgr;&egr;) of the surface of its insulating layer while actually measuring the bending life. Then, the distortional change quantity (&Dgr;&egr;) of the surface of the insulating layer of the wire or the like regarded as the object for predicting the bending life is calculated (CAE analysis or the like). The bending life of the wire or the like is predicted by collating the calculated distortional change quantity (&Dgr;&egr;) of the wire or the like serving as the prediction object with the aforementioned master curve. The bending life can be correctly predicted regardless of product conditions of the wire or the like.

Abstract: The invention provides a method of simulating and estimating the minimum lifetime under repeated bending for a wire harness containing a plurality of electrical cables, by applying a compact and lightly equipped device. To this end, representative electrical cables, contained in the wire harness, are subjected to flexing and stretching until they fail under repeated bending, so that the number of bending cycles is obtained for each representative electrical cable. The minimum lifetime for the wire harness can then be estimated on the basis of the shortest cable lifetime that can be found among all the representative electrical cables tested.

Abstract: There is provided a bend-test device for wire harnesses, capable of handling a plurality of samples at the same time. The bend-test device includes a fixed frame unit, a hinge unit with a fulcrum axis, and a mobile frame unit connected to the fixed frame unit via the hinge unit in a freely pivotable manner around the fulcrum axis. The fixed frame unit includes fixed-side panels respectively including holder holes, each of which holds a grommet carrying a wire harness. The fixed-side panels are arranged in a parallel relation to each other, and aligned perpendicular to the direction of the fulcrum axis, in a freely mountable and removable manner. Likewise, the mobile frame unit includes mobile-side panels respectively including holder holes, each of which holds another grommet carrying the wire harness. The mobile-side panels are arranged as mentioned above, so that each of the mobile-side panels can be opposed to a corresponding one among the fixed-side panels.