通过对某交流500 k V复合绝缘子断裂情况进行分析,认为由电场畸变引起的局部放电是促使绝缘子断裂的原因。利用有限元软件ANSYS建立500 k V复合绝缘子几何模型,对其电场分布特性进行仿真计算。结果表明:绝缘子断裂位置位于高压端附近的...通过对某交流500 k V复合绝缘子断裂情况进行分析,认为由电场畸变引起的局部放电是促使绝缘子断裂的原因。利用有限元软件ANSYS建立500 k V复合绝缘子几何模型,对其电场分布特性进行仿真计算。结果表明:绝缘子断裂位置位于高压端附近的场强极大值处,当此处护套芯棒界面存在气隙缺陷时,护套内外局部电场均出现不同程度的增大,且内外场强存在较大差值易造成护套击穿。电场不均匀引起的局部放电进一步会沿电场方向形成碳化通道,在水气及酸性物质的影响下,绝缘子力学性能会极大降低,严重时导致绝缘子断裂。展开更多
A new method using lead coated glass fiber to produce continuous wire for battery grid of electric vehicles （EVs） and hybrid electric vehicles （HEVs） was introduced. Under equal flow, both the maximum and minimum ...A new method using lead coated glass fiber to produce continuous wire for battery grid of electric vehicles （EVs） and hybrid electric vehicles （HEVs） was introduced. Under equal flow, both the maximum and minimum theoretical value of gap size were studied and estimation equation was established. The experimental results show that the gap size is a key parameter for the continuous coating extrusion process. Its maximum value （Hmax） is 0.24 mm and the minimum one （Hmin） is 0.12mm. At a gap size of 0.18 mm, the maximum of metal extrusion per unit of time and optimal coating speed could be obtained.展开更多
A novel elastic sandwich metamaterial plate with composite periodic rod core is designed,and the frequency band-gap characteristics are numerically and experimentally investigated.The finite element and spectral eleme...A novel elastic sandwich metamaterial plate with composite periodic rod core is designed,and the frequency band-gap characteristics are numerically and experimentally investigated.The finite element and spectral element hybrid method(FE-SEHM)is developed to obtain the dynamic stiffness matrix of the sandwich metamaterial plate.The frequency response curves of the plate structure under the harmonic excitation are calculated using the presented numerical method and validated by the vibration experiment.By comparing with the frequency response curves of sandwich metamaterial plate with pure elastic rod core,improved band-gap properties are achieved from the designed metamaterial plate with composite periodic rod core.The elastic metamaterial plate with composite periodic rod core can generate more band-gaps,so it can suppress the vibration and elastic wave propagation in the structure more effectively.展开更多
The equipment has a high and strict requirement of dynamic seals, especially working with Long stroke reciprocating motion under a sandy condition and with a great deal of gas. The seal form of power cylinder on the u...The equipment has a high and strict requirement of dynamic seals, especially working with Long stroke reciprocating motion under a sandy condition and with a great deal of gas. The seal form of power cylinder on the underground part of hydraulic power rodless type oil extraction equipment is studied. We design three seal structures, do the performance testing and the life testing with related equipment. It turned out that the seal form that combines gap seal with sand prevention techniques has high performance, longer life. The power cylinder works stably and reliably.展开更多
文摘通过对某交流500 k V复合绝缘子断裂情况进行分析,认为由电场畸变引起的局部放电是促使绝缘子断裂的原因。利用有限元软件ANSYS建立500 k V复合绝缘子几何模型,对其电场分布特性进行仿真计算。结果表明:绝缘子断裂位置位于高压端附近的场强极大值处,当此处护套芯棒界面存在气隙缺陷时,护套内外局部电场均出现不同程度的增大,且内外场强存在较大差值易造成护套击穿。电场不均匀引起的局部放电进一步会沿电场方向形成碳化通道,在水气及酸性物质的影响下,绝缘子力学性能会极大降低,严重时导致绝缘子断裂。
文摘A new method using lead coated glass fiber to produce continuous wire for battery grid of electric vehicles （EVs） and hybrid electric vehicles （HEVs） was introduced. Under equal flow, both the maximum and minimum theoretical value of gap size were studied and estimation equation was established. The experimental results show that the gap size is a key parameter for the continuous coating extrusion process. Its maximum value （Hmax） is 0.24 mm and the minimum one （Hmin） is 0.12mm. At a gap size of 0.18 mm, the maximum of metal extrusion per unit of time and optimal coating speed could be obtained.
基金the National Natural Science Foundation of China(No.11761131006)the Research Team Project of Heilongjiang Natural Science Foundation under Grant No.TD2020A001.
文摘A novel elastic sandwich metamaterial plate with composite periodic rod core is designed,and the frequency band-gap characteristics are numerically and experimentally investigated.The finite element and spectral element hybrid method(FE-SEHM)is developed to obtain the dynamic stiffness matrix of the sandwich metamaterial plate.The frequency response curves of the plate structure under the harmonic excitation are calculated using the presented numerical method and validated by the vibration experiment.By comparing with the frequency response curves of sandwich metamaterial plate with pure elastic rod core,improved band-gap properties are achieved from the designed metamaterial plate with composite periodic rod core.The elastic metamaterial plate with composite periodic rod core can generate more band-gaps,so it can suppress the vibration and elastic wave propagation in the structure more effectively.
文摘The equipment has a high and strict requirement of dynamic seals, especially working with Long stroke reciprocating motion under a sandy condition and with a great deal of gas. The seal form of power cylinder on the underground part of hydraulic power rodless type oil extraction equipment is studied. We design three seal structures, do the performance testing and the life testing with related equipment. It turned out that the seal form that combines gap seal with sand prevention techniques has high performance, longer life. The power cylinder works stably and reliably.
