This work proposes a new method to evaluate the electrical contact performance of aviation connectors by in-situ measurement of broadband impedance. The broadband impedance of the wire-connector under corrosive environments is measured using an inductive coupled measurement scheme, which can be conducted under operating conditions. By observing variations in the inductance and resonant frequency of measured impedance, the degradation of the connectors can be assessed more accurately and intuitively. Experiments reveal a quasi-linear degradation correspondence between the impedance of connectors and corrosion duration. Moreover, the impedance of connectors is more sensitive to corrosion-induced degradation compared to resistance, which means that potential damage to the connector can be detected earlier through the proposed in-situ impedance measurement, allowing for better-informed risk management and timely repair or replacement, particularly in safety-critical situations.

The wear of the contact surface caused by relative sliding can degrade the electrical contact performance of the aviation electrical connector. This work mimics contact surface wear through repeated plugging and unplugging experiments. A non-contact in-circuit impedance measurement method using a dual inductive probe technique is employed to continuously measure the impedance of the circuit under test, which comprises the connector and connecting wire, across the 1 MHz to 150 MHz frequency range during the experiment. Subsequently, the electrical parameters of the degraded connector are determined by combining a lumped transmission line model of the connecting wire with a broadband impedance model of the connector, based on the measured impedance of the circuit under test. The experimental results indicate that as the number of plugging and unplugging cycles increases, the resonant frequency observed in the broadband impedance measurements decreases. This phenomenon is primarily attributed to an increase in the contact capacitance of the connector due to wear on the contact surfaces. After 2000 test cycles, the resonant frequency of the circuit under test decreased by 1.25 MHz. Parameter identification revealed that the contact capacitance of the connector increased from 11.6 pF to 48.9 pF, a 4.22-fold rise. Meanwhile, the DC contact resistance increased by only 1.15 times over the same period. These findings suggest that contact capacitance is a more sensitive indicator of early degradation than DC contact resistance.

This article proposes an uncertainty analysis method for crosstalk in cable bundles based on the stochastic reduced order modeling (SROM) method. First, a multipoint bundled random cable bundle modeling method is proposed by modifying the random midpoint displacement method and the iterative perturbation method for deterministic calculation of nonuniform cable crosstalk are demonstrated. According to the sensitivity analysis results of crosstalk parameters and the geometric characteristics of the cable bundle, dimensionality reduction is applied to the cable model. Subsequently, SROM is applied to perform uncertainty analysis on crosstalk for randomly sampled cable bundles, and the results are compared with a reference benchmark obtained via Monte Carlo method. Finally, experimental tests on cable crosstalk are conducted, validating the effectiveness of the proposed uncertainty analysis method for random cable bundle crosstalk.

This article is concerned with how crosstalk amplitudes of multiconductor polyvinyl chloride cables vary with heating temperatures and time to determine thermal effects on the cables in realistic conditions and thus proposes a method to estimate aging rates and accelerating ratios with respect to the variation of crosstalk amplitudes. First, the mechanism of thermal effects on the crosstalk of multiconductor cables is analyzed: high temperatures accelerate chemical reactions in insulating materials to change their microstructures as well as their permittivity. The resulting variation of permittivity leads to changes in crosstalk amplitude. Then, experiments are conducted to measure crosstalk amplitudes of cables in a thermal chamber. Finally, based on measured results, time-based variations of crosstalk amplitudes at different temperatures are demonstrated and the equivalent chemical reaction rates are calculated. By fitting the rates with the Arrhenius equation, accelerating ratios between different temperatures are obtained.

This paper is concerned with calculating the phase stability of a phase stable cable with multi-physics coupling simulations. A three-dimensional electromagnetic-thermal-flow-mechanics multi-physics coupling model is established to simulate the phase stable cable operating in air. The simulation results demonstrate that the electric field distribution of the corrugated cable shows differences from that of a normal coaxial cable around the outer conductor, i.e., the electric field is stronger around the sharp points of the outer conductor than the blunt points, which elevates the voltage endurance requirement of the cable and the risk of breakdown during the transmission of high power. Regarding the thermal deformation, simulations reveal that the corrugated outer conductor restrains the insulation from expanding along both the cross-section direction and the axial direction, and the thermal expansion might be manipulated through the proper design of the outer conductor parameters. Finally, the consistency between the simulated and measured results of phase stability witnesses the validity of the multi-physics coupling model, and its accuracy might be refined with more precise material properties.

A nonuniform orthogonal mesh generation scheme, namely, the integer-varying meshes, is proposed to model realistic conductor systems with the partial element equivalent circuit (PEEC) method in this article. The integer-varying meshes resolve the weak geometry description ability and unrealistic of uniform meshes, thus yielding frequency-independent circuits for skin-effect modelling. In comparison to generic nonuniform meshes, the calculation of the partial elements can be significantly accelerated by the integer-varying meshes in coordination with the partial inductance approximation scheme and tabulation. The accuracy of the partial inductance approximation scheme is validated for partial inductance units with a wide range of aspect ratios and relative distance. In addition, to deal with the cells with extreme aspect ratios generated by the integer-varying meshes, stable model order-reduced formulas for partial elements are adopted; such proposed model, at the same time, is able to speed up the calculation, when the formula for the partial self potential coefficient is modified for stability at extreme aspect ratios. Through three numerical examples, including an L-shaped trace over a ground, a single loop coil and a 3-D spiral inductor, the efficiency of the integer-varying meshes with the partial inductance approximation and tabulation is verified by comparison to the case without approximation or tabulation, and the results demonstrate good consistency to the references.