CN111737903A

CN111737903A - High-frequency performance prediction method of connector under action of vibration stress

Info

Publication number: CN111737903A
Application number: CN202010591952.0A
Authority: CN
Inventors: 李庆娅; 高锦春; 谢刚; 周雨奇; 王紫任; 毕凌宇; 宋凯旋; 王文佳; 罗俊宇
Original assignee: Beijing University of Posts and Telecommunications
Current assignee: Beijing University of Posts and Telecommunications
Priority date: 2020-06-24
Filing date: 2020-06-24
Publication date: 2020-10-02
Anticipated expiration: 2040-06-24
Also published as: CN111737903B

Abstract

The invention discloses a high-frequency performance prediction method of a connector under the action of vibration stress. The invention comprises the following steps: step one), a vibration test platform is set up, so that the radio frequency coaxial connector is subjected to vibration tests, and contact pressure and high-frequency parameters with different degradation degrees are measured; step two), establishing an equivalent circuit model comprising a transmission line and a degraded contact surface, wherein the contact surface model comprises resistance, capacitance and inductance parameters; step three), establishing a relation model of resistance, capacitance and contact pressure respectively, establishing a relation model of inductance and equivalent length, and establishing a relation model of contact pressure, deformation and equivalent length; and step four), simulating based on the actually measured contact pressure and the established model, predicting the high-frequency performance, and comparing with the test result. The invention researches a high-frequency performance prediction method of the connector under the action of vibration stress from the aspects of experimental design and theoretical derivation, and is suitable for analyzing coaxial connectors with similar structures.

Description

High-frequency performance prediction method of connector under action of vibration stress

Technical Field

The invention relates to a high-frequency performance prediction method of a connector under the action of vibration stress, which is established on the basis of comprehensive analysis methods such as theoretical modeling and finite element simulation and the like under different degradation conditions and belongs to the technical field of electrical contact reliability of a communication system.

Background

The connector is used as a basic component, is mainly used for realizing the transmission and control of electric signals and the electric connection function between electronics and electrical equipment, is widely applied to various fields of aerospace, aviation, military equipment, electronics, communication and the like, and the reliability of the connector directly influences the safe and reliable operation of a system. The contact member composed of the contact pin and the jack is a core part of the connector, and the inserting and extracting processes are main modes for realizing electric connection, so that the contact member inside the connector is easily subjected to mechanical abrasion, the contact state is changed, the reliability of the connector is influenced, and the reliability of a system is further influenced to a certain degree.

Connectors are subject to a variety of environmental stresses during storage and use, with vibrational stresses being one of the major environmental factors affecting connector reliability. Under the action of the vibration stress, the relative motion between the jack and the pin of the connector is generated. Under the repeated action of long-term vibration stress, the jack can generate micro deformation, the phenomena of stress relaxation and elastic fatigue occur, the contact pressure is reduced, the contact performance of the connector is degraded, and the reliability is reduced. Degradation of the contact surfaces of the connector can degrade electrical parameters including contact resistance, high frequency parameters (insertion loss, return loss, voltage standing wave ratio, etc.), passive intermodulation, electromagnetic compatibility, etc., thereby affecting the proper transmission of communication signals.

Therefore, it is necessary to establish a method for predicting the high-frequency performance of the connector under the action of vibration stress, so as to provide a certain reference for reliability evaluation of the connector and establishment of a connector quality detection standard.

Disclosure of Invention

In view of the above technical problems, the present invention provides a method for predicting high frequency performance under the action of vibrational stress, which is suitable for the research of predicting high frequency performance of a device under the action of stress.

In order to meet the requirements, the invention provides the following scheme:

step one) accelerated test and degradation test

Firstly, a vibration experiment platform is built by adopting a signal source, an amplifier and a vibration table, a clamp required by the experiment is designed and processed, then an N-type contact pin and an N-type female-to-female connector are fixed on the vibration table by using the clamp, and then vibration acceleration tests are respectively carried out on the connector for 15 hours and 30 hours. The N-type male pin and the N-type female-to-female connector were removed, and the deformation of the insertion hole of the N-type female-to-female connector was observed to different degrees. The maximum stiction was obtained by testing an N-type connector pin and female turn connector without vibration test using a tensile machine, thereby obtaining connector samples that were not degraded and subjected to vibration tests for 15 hours and 30 hours and had contact pressures of 5.35N, 3.27N, and 0.62N, respectively. The high-frequency parameters of the connector samples are measured by a vector network analyzer, and the analysis frequency is 0.1 MHz-1.0 GHz.

Step two) equivalent circuit and parameter modeling

When a vector network analyzer is used for testing a connector sample, the outer sides of the N-type female-to-female connectors are respectively connected with the SMA-type male-to-N-type female connectors for connection with the analyzer. Considering that certain contacts exist when the three connectors are connected and the connectors are equivalent to transmission lines, an equivalent circuit model comprising the transmission lines and degraded contact surfaces is established, and the model comprises contact resistance, capacitance and inductance parameters. By testing the surface roughness of the N-type contact pin in the original state, the contact surface is equivalent to a complete elastic contact, and a relation model of contact resistance, capacitance and contact pressure is respectively established. And (3) considering the influence of the contact pressure on the inductance, introducing an equivalent length parameter, and establishing a relation model of the parameter and the inductance. After the N-type female-to-female connector is subjected to a vibration experiment, the jack can be loosened, and the loosening degree is measured by introducing the deformation parameter of the loosening of the jack. And establishing a finite element simulation model of the deformation quantity and the equivalent length of the loose jack to obtain different relation models of the deformation quantity, the equivalent length and the contact pressure of the loose jack.

Step three) prediction of high-frequency performance parameters

And obtaining corresponding resistance, capacitance and inductance according to the actually measured contact pressure and the established relation model of the contact resistance, capacitance, inductance and contact pressure, and substituting the resistance, capacitance and inductance into the established circuit model for simulation, thereby predicting the high-frequency performance under different contact pressures and comparing the high-frequency performance with the test result.

The high-frequency performance prediction method of the connector under the action of the vibration stress is based on comprehensive analysis methods such as theoretical modeling and finite element simulation, predicts the high-frequency performance of the connector after being inserted and exposed in a vibration environment for a certain time, provides theoretical support for the high-frequency performance prediction of a device under the action of the stress, and is suitable for the high-frequency performance prediction of the related device under the action of the stress. The invention has the following advantages: predicting the high-frequency performance based on the jack stress relaxation phenomenon caused by the connector under the action of the vibration stress; aiming at an equivalent circuit model of the connector, a relation model of contact resistance, capacitance, inductance and contact pressure is established; and simulating the high-frequency performance under the action of different contact pressures.

Drawings

FIG. 1 is a schematic diagram of the technical scheme of the invention.

Detailed Description

The invention is explained in detail below with reference to the figures and the implementation steps. The following description case uses an N-type female-to-female radio frequency coaxial connector as a research object, but the present embodiment is not limited to the present invention, and the high frequency performance prediction can be performed by using the analysis method of the present invention whenever the coaxial structure of the present invention is used as an analysis object.

As shown in fig. 1, the high-frequency performance prediction method of the present invention mainly includes surface physical modeling and experimental testing, and establishes high-frequency performance prediction under the action of vibration stress for the jack inner conductor of the coaxial connector by using a method combining theoretical analysis and finite element simulation.

The method comprises the following steps of firstly, carrying out an acceleration test, and carrying out vibration degradation tests of different degrees on the jacks of the N-type connector. A vibration experiment platform is built by adopting a signal source, an amplifier and a vibration table, a clamp required by the experiment is designed and processed, then an N-type contact pin and an N-type female-to-female connector are fixed on the vibration table by using the clamp, and then vibration acceleration tests are respectively carried out on the connector for 15 hours and 30 hours. The N-type male pin and the N-type female-to-female connector were removed, and the deformation of the insertion hole of the N-type female-to-female connector was observed to different degrees. The maximum stiction was obtained by testing an N-type connector pin and female turn connector without vibration test using a tensile machine, thereby obtaining connector samples that were not degraded and subjected to vibration tests for 15 hours and 30 hours and had contact pressures of 5.35N, 3.27N, and 0.62N, respectively. The high-frequency parameters of the connector samples are measured by a vector network analyzer, and the analysis frequency is 0.1 MHz-1.0 GHz.

And secondly, when a vector network analyzer is used for testing a connector sample, in order to be connected with the analyzer, the outer sides of the N-type female-to-female connectors are respectively connected with the SMA-type male-to-N-type female connectors. Considering that certain contacts exist when the three connectors are connected and the connectors are equivalent to transmission lines, an equivalent circuit model comprising the transmission lines and degraded contact surfaces is established, and the model comprises contact resistance, capacitance and inductance parameters. By testing the surface roughness of the N-type contact pin in the original state, the contact surface is equivalent to a complete elastic contact, and a relation model of contact resistance, capacitance and contact pressure is respectively established. And (3) considering the influence of the contact pressure on the inductance, introducing an equivalent length parameter, and establishing a relation model of the parameter and the inductance. After the N-type female-to-female connector is subjected to a vibration experiment, the jack can be loosened, and the loosening degree is measured by introducing the deformation parameter of the loosening of the jack. And establishing a finite element simulation model of the deformation quantity and the equivalent length of the loose jack to obtain different relation models of the deformation quantity, the equivalent length and the contact pressure of the loose jack.

And thirdly, obtaining corresponding resistance, capacitance and inductance according to the actually measured contact pressure and the established relation model of the contact resistance, capacitance, inductance and contact pressure, substituting the resistance, capacitance and inductance into the established circuit model for simulation, predicting high-frequency performance under different contact pressures, and comparing the high-frequency performance with a test result.

Claims

1. A high-frequency performance prediction method of a connector under the action of vibration stress is characterized by comprising the following steps:

firstly, a vibration experiment platform is set up, degradation of the connector is carried out to different degrees, and contact pressure and high-frequency performance parameters of the connector with different degradation degrees are tested;

then, an equivalent circuit model including the transmission line and the degraded contact surface is established, and the contact surface model includes contact resistance, capacitance and inductance parameters. And establishing a relation model of contact resistance, capacitance and contact pressure respectively according to the roughness model of the contact surface, establishing a relation model of inductance and equivalent length, establishing a finite element simulation model of deformation quantity and equivalent length of the loose jack, and obtaining the relation model of contact pressure, deformation quantity and equivalent length.

And finally, obtaining corresponding resistance, capacitance and inductance according to the actually measured contact pressure and the established relation model, substituting the resistance, capacitance and inductance into a circuit model for simulation, predicting high-frequency performance under different contact pressures, and comparing the high-frequency performance with a test result.

2. The method for predicting the high-frequency performance of the connector under the action of the vibration stress as claimed in claim 1, wherein in the first step, connector samples with different degradation degrees are determined through a vibration acceleration test, and the contact pressure and the high-frequency parameters are tested.

3. The method for predicting the high-frequency performance of the connector under the action of the vibration stress as claimed in claim 1, wherein in the second step, a relation model of contact resistance, capacitance and contact pressure is established based on an elastic Hertz contact theory and a roughness model. And simultaneously establishing the relation between the inductance and the equivalent length, and establishing the relation between the contact pressure, the equivalent length and the loosening deformation according to finite element simulation.

4. The method for predicting the high-frequency performance of the connector under the action of the vibration stress as claimed in claim 1, wherein the parameters in the relation model established in the third step are substituted into the equivalent circuit model, and the high-frequency parameters under different degradation degrees are simulated and predicted.