Wiring simulation tool slashes lead times, lowers evaluation costs

A new tool to help engineers cut lead time and costs in the design and production of vehicle wiring harnesses has been developed.

The simulation tool, called Wiring Harness Bend Fatigue Simulation Tool, was developed by a global team of Delphi Packard Electrical/Electronic Architecture engineers, enables vehicle designers and engineers to shorten the wiring harness design cycle without compromising the quality of the wiring harness. "This tool allows us to identify, and then design in, the optimal wiring harness for a vehicle in a virtual environment," says Robert Seidler, engineering director, Global Core and Electrical/Electronic Architecture, Delphi. "Since engineers can predict wiring harness fatigue over the life of a vehicle, any potential design flaws can be corrected before the vehicle is built. It also affords the customer the freedom to make late design changes without having to worry it will delay their start of production." All this translates into Delphi's customers being able to feel even more confident in their ability to cost-effectively design a durable, efficient wiring harness that will last over the life of the vehicle. A vehicle's wiring harness is a complicated assembly of cables and grommets surrounded by insulation. It typically is installed between static and moving vehicle body parts, such as doors, lift gates, and trunk lids. With repeated opening and closing of these parts, the wiring systems experience a significant amount of bending deformation. Wiring harness durability depends on the ability of the cables to withstand this bending fatigue over time and can be simulated in three steps: First by predicting the behaviour of the wiring harness during flex applications; secondly by calculating the stress that will be applied to the harness bundle and cables; and finally by estimating the fatigue life of the harness. Traditionally, harness durability could only be evaluated once the vehicle and wiring harness prototype had been designed and built. Cables in that newly-designed prototype were physically tested for strength and durability, redesigned and rebuilt, and then tested again — a costly, time-consuming process. Using the new Delphi simulation tool during harness design shortens the process without compromising quality and cost. By applying unique algorithms to data on the physical properties of the cable, grommet, and insulation, engineers can model real-world wiring harness performance before the actual vehicle and harness are built. "This approach is technically more robust, scientifically more accurate, and considerably faster than the validation process used in the past," said Jun Ma, engineering manager, simulation, Delphi Packard Electrical/Electronic Architecture. "Given a wide range of materials and conditions, our theoretical analysis can predict durability and help engineers determine the best design in a matter of days, significantly reducing validation time."