Thermal analysis and thermal diagnose are important for small power connector especially in electronic devices since their structure is usually compact. In this paper thermal behavior of small power connector was inve...Thermal analysis and thermal diagnose are important for small power connector especially in electronic devices since their structure is usually compact. In this paper thermal behavior of small power connector was investigated. It was found that the contact resistance increased due to the Joule beating, and that increased contact resistance produced more Joule heating; this mutual action causes the connector to lose efficiency. The thermal distribution in the connector was analyzed using finite element method （FEM）. The failure mechanism is discussed. It provides basis for improving the structure. The conclusion was verified by experimental results.展开更多
The effect of dust particles on electric contacts and a hazardous size range of hard dust particles using a rigid model were discussed before. As further research, elastic-plastic model of finite element analysis was ...The effect of dust particles on electric contacts and a hazardous size range of hard dust particles using a rigid model were discussed before. As further research, elastic-plastic model of finite element analysis was established in this work, which is closer to real condition. In this work, the behavior of large size and small size particles, and the influence of particles hardness were investigated. The calculating result of small-size particles presents a general hazardous size coefficient for different contact surface morphology; for large-size particles, it presents a hazardous size coefficient for complicated composition of the dust. And the effect of the dust shape is also discussed.展开更多
A kind of low power connector used e.g. in household appliances was partly burned in routine experiment. The heat sources were four paralleled contacts constructed by springs (Sn/CuSn-alloy) in socket and a plug sheet...A kind of low power connector used e.g. in household appliances was partly burned in routine experiment. The heat sources were four paralleled contacts constructed by springs (Sn/CuSn-alloy) in socket and a plug sheet (Ni/Steel) while mating. The contact interfaces were detected by scanning electronic microscope (SEM) and X-ray energy dispersive spectros- copy (XEDS), obvious wear tracks and various contaminants, including element Si, Al, Na, K, S, Cl, O, etc., were found. The contamination degrees on the four paralleled contacts were different, so that the ratio of average contact resistance on the four contacts was about 5:8:3:1. The maximum contact resistance on contacts of the plug sheet reached 28 ?. The main failure rea- sons were fretting and contamination between the contact interfaces. Fretting simulation showed that connection resistance of connectors was raised up, even to ohms level. When the current increased to 5 A, the socket housing was heated and decom- posed. By the thermal analysis, it was estimated that the connector would be burned under the lower current if the current was not evenly distributed on the four paralleled contacts caused by uneven contamination. Improvement methods for connector failure are also discussed.展开更多
The conventional poststack inversion uses standard recursion formulas to obtain impedance in a single trace.It cannot allow for lateral regularization.In this paper,ID edge-preserving smoothing(EPS)fi lter is extended...The conventional poststack inversion uses standard recursion formulas to obtain impedance in a single trace.It cannot allow for lateral regularization.In this paper,ID edge-preserving smoothing(EPS)fi lter is extended to 2D/3D for setting precondition of impedance model in impedance inversion.The EPS filter incorporates a priori knowledge into the seismic inversion.The a priori knowledge incorporated from EPS filter preconditioning relates to the blocky features of the impedance model,which makes the formation interfaces and geological edges precise and keeps the inversion procedure robust.Then,the proposed method is performed on two 2D models to show its feasibility and stability.Last,the proposed method is performed on a real 3D seismic work area from Southwest China to predict reef reservoirs in practice.展开更多
文摘Thermal analysis and thermal diagnose are important for small power connector especially in electronic devices since their structure is usually compact. In this paper thermal behavior of small power connector was investigated. It was found that the contact resistance increased due to the Joule beating, and that increased contact resistance produced more Joule heating; this mutual action causes the connector to lose efficiency. The thermal distribution in the connector was analyzed using finite element method （FEM）. The failure mechanism is discussed. It provides basis for improving the structure. The conclusion was verified by experimental results.
文摘The effect of dust particles on electric contacts and a hazardous size range of hard dust particles using a rigid model were discussed before. As further research, elastic-plastic model of finite element analysis was established in this work, which is closer to real condition. In this work, the behavior of large size and small size particles, and the influence of particles hardness were investigated. The calculating result of small-size particles presents a general hazardous size coefficient for different contact surface morphology; for large-size particles, it presents a hazardous size coefficient for complicated composition of the dust. And the effect of the dust shape is also discussed.
文摘A kind of low power connector used e.g. in household appliances was partly burned in routine experiment. The heat sources were four paralleled contacts constructed by springs (Sn/CuSn-alloy) in socket and a plug sheet (Ni/Steel) while mating. The contact interfaces were detected by scanning electronic microscope (SEM) and X-ray energy dispersive spectros- copy (XEDS), obvious wear tracks and various contaminants, including element Si, Al, Na, K, S, Cl, O, etc., were found. The contamination degrees on the four paralleled contacts were different, so that the ratio of average contact resistance on the four contacts was about 5:8:3:1. The maximum contact resistance on contacts of the plug sheet reached 28 ?. The main failure rea- sons were fretting and contamination between the contact interfaces. Fretting simulation showed that connection resistance of connectors was raised up, even to ohms level. When the current increased to 5 A, the socket housing was heated and decom- posed. By the thermal analysis, it was estimated that the connector would be burned under the lower current if the current was not evenly distributed on the four paralleled contacts caused by uneven contamination. Improvement methods for connector failure are also discussed.
基金The National Key S&T Special Projects (No. 2017ZX05008004-008)the National Natural Science Foundation of China (No. 41874146)+2 种基金the National Natural Science Foundation of China (No. 41704134)the Innovation Team of Youth Scientific and Technological in Southwest Petroleum University (No. 2017CXTD08)the Initiative Projects for Ph.Din China West Normal University (No. 19E063)
文摘The conventional poststack inversion uses standard recursion formulas to obtain impedance in a single trace.It cannot allow for lateral regularization.In this paper,ID edge-preserving smoothing(EPS)fi lter is extended to 2D/3D for setting precondition of impedance model in impedance inversion.The EPS filter incorporates a priori knowledge into the seismic inversion.The a priori knowledge incorporated from EPS filter preconditioning relates to the blocky features of the impedance model,which makes the formation interfaces and geological edges precise and keeps the inversion procedure robust.Then,the proposed method is performed on two 2D models to show its feasibility and stability.Last,the proposed method is performed on a real 3D seismic work area from Southwest China to predict reef reservoirs in practice.
