A Weibull model to characterize lifetimes of aluminum alloy electrical wire connections

Samples of 12-gauge aluminum alloy electrical conductor wire and three different connector torques were tested to 1000 cycles using an accelerated test method which is independent of commercially available connectors. A Weibull probability model was fitted to the number of cycles to failure, for each of the torques for each alloy. For all groups, beta (Weibull shape parameter, describing the spread in observed connection lifetimes) is in the range of 1-2. The parameter alpha (location parameter, describing the characteristic connector lifetime) increased as connector torque increased, and had a value characteristic of the alloy used. Assuming a Weibull model for failure of electrical connectors for aluminum wire, acceptance plans were developed to discriminate between alloys with different characteristic lifetimes. Experiments confirmed the ability of the acceptance plans to clearly discriminate between known alloys.<>