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This paper mainly studies the effects of low temperature on the reliability of electrical connectors. Based on the theory of constant stress accelerated life test, this paper provides a kind of scheme of low temperature reliability test, which includes magnitude of the temperature stresses, the parameters measured during the test and so on. The detecting circuit is designed; the test is carried out and finally, according to the experimental data, it can be concluded that 1) both the absolute change and the relative change of contact resistance are small for each temperature stress; 2) the forecast data show a tendency toward slightly lower value of contact resistance for each low temperature stress; 3) the lower the test temperature stress, the smaller the value of contact resistance, but the difference in contact resistance is tiny; 4) stress analysis of samples under low temperature is also helpful for correctly evaluating the effects of low temperature on the reliability of electrical connectors.

The steady-state thermal analysis models are established based on the thermal analysis of the Electric connectors. With the consideration to the internal heat conduction and the convection cooling, the three-dimensional solid model is imposed by the reasonable loads and boundary conditions and analyzed by ANSYS thermal analysis module. The numerical analysis is made on the temperature field of a certain type of Electric connectors at different environmental temperature and different working current. The simulation results are compared with the monitoring test data.

The discontinuous finite element method (DFEM) is used to investigate the coupled radiation-conduction heat transfer in an irregular medium, and the highly accurate solutions for several typical media are numerically obtained. Comparing with the traditional continuous finite element method, the computational domain in the DFEM application is discretized into unstructured meshes that are assumed to be separated from each other. The shape function construction, field variable approximation, and numerical solutions are obtained for every single element. The continuity of the computational domain is maintained by modeling a numerical flux with the up-winding scheme. Thus the DFEM has the salient feature of geometry flexibility and simultaneously supports locally conservative solutions. The DFEM discretization for the radiative transfer equation and the energy diffusion equation are first presented, and the accuracies of the DFEM for coupled radiation-conduction heat transfer problems are verified. Combined radiation-conduction heat transfer problems in several irregular media are afterward solved, and the highly accurate DFEM solutions are presented.