模组循环过程中导致的单个电池的体积变化,会不可避免的影响临近电池的受力状态,即单个电池在模组中所受到的约束是一个不可忽略的因素。本文研究了锂离子电池在约束外压力条件下充放电过程中的受力情况及影响因素。本文采用了外压力传...模组循环过程中导致的单个电池的体积变化,会不可避免的影响临近电池的受力状态,即单个电池在模组中所受到的约束是一个不可忽略的因素。本文研究了锂离子电池在约束外压力条件下充放电过程中的受力情况及影响因素。本文采用了外压力传感器和充放电测试柜测试电池循环过程中的外压力变化。结果显示,锂离子电池充放电过程中实际受力与电压变化趋势一致,这是由于充电过程电池体积膨胀,放电过程电池体积回复所导致的。此外电池充放电过程中的实际压力会偏离设定值,变化范围与初始约束时的荷电状态(State of Charge,SOC)有关。低SOC时受约束电池表现出更大的压力波动范围。展开更多
In this study, the undrained behaviour of silt under low stress level is studied. An effective preparation method for built-in silt samples in the triaxial test was firstly developed. By triaxial testing of samples at...In this study, the undrained behaviour of silt under low stress level is studied. An effective preparation method for built-in silt samples in the triaxial test was firstly developed. By triaxial testing of samples at low confining pressures it was found that silt easily loses stability and liquefies. Loose silt may show temporary liquefaction under static loading, and develop full liquefaction under cyclic loading. The most important factors influencing the silt behaviour are porosity, confining pressure, consolidation state, cyclic loading level and number of cycles. The maximum obtainable shear stress is primarily a function of the confining pressure and the internal frictional angle. The actual structure of the silt material is the key factor in controlling its behaviour.展开更多
This paper presents an investigation on strength of cement deep mixing （CDM） mixture. Four typical works of offshore or land-based projects are introduced. With samples from these projects and laboratory tests, stat...This paper presents an investigation on strength of cement deep mixing （CDM） mixture. Four typical works of offshore or land-based projects are introduced. With samples from these projects and laboratory tests, statistical analysis is made on the increment law of the strength of cement-soil mixture with different amount of cement, and strengths under different working conditions are compared. It is found that the amount of cement in the cement-soil mixture is closely related to the unconfined compressive strength of the mixture. At the age of 90 d,the unconfined compressive strength of the cement-soil mixture increased by 0.054 MPa—0.124 MPa with each cement increasing 10 kg/m3 in the cement-soil mixture, averagely increased by 0.085 MPa, while that at the age of 120 d increased by 1100 in comparison.The quality of the cement-soil mixture should be comprehensively evaluated in accordance with the trimmed average of strength, coefficient of variation and rock quality designation （RQD） indicators of sampling ratio.展开更多
文摘模组循环过程中导致的单个电池的体积变化,会不可避免的影响临近电池的受力状态,即单个电池在模组中所受到的约束是一个不可忽略的因素。本文研究了锂离子电池在约束外压力条件下充放电过程中的受力情况及影响因素。本文采用了外压力传感器和充放电测试柜测试电池循环过程中的外压力变化。结果显示,锂离子电池充放电过程中实际受力与电压变化趋势一致,这是由于充电过程电池体积膨胀,放电过程电池体积回复所导致的。此外电池充放电过程中的实际压力会偏离设定值,变化范围与初始约束时的荷电状态(State of Charge,SOC)有关。低SOC时受约束电池表现出更大的压力波动范围。
基金This research is partly supported by the National Natural Science Foundation(No.50009002)863(No.2001AA616020)projects.
文摘In this study, the undrained behaviour of silt under low stress level is studied. An effective preparation method for built-in silt samples in the triaxial test was firstly developed. By triaxial testing of samples at low confining pressures it was found that silt easily loses stability and liquefies. Loose silt may show temporary liquefaction under static loading, and develop full liquefaction under cyclic loading. The most important factors influencing the silt behaviour are porosity, confining pressure, consolidation state, cyclic loading level and number of cycles. The maximum obtainable shear stress is primarily a function of the confining pressure and the internal frictional angle. The actual structure of the silt material is the key factor in controlling its behaviour.
文摘This paper presents an investigation on strength of cement deep mixing （CDM） mixture. Four typical works of offshore or land-based projects are introduced. With samples from these projects and laboratory tests, statistical analysis is made on the increment law of the strength of cement-soil mixture with different amount of cement, and strengths under different working conditions are compared. It is found that the amount of cement in the cement-soil mixture is closely related to the unconfined compressive strength of the mixture. At the age of 90 d,the unconfined compressive strength of the cement-soil mixture increased by 0.054 MPa—0.124 MPa with each cement increasing 10 kg/m3 in the cement-soil mixture, averagely increased by 0.085 MPa, while that at the age of 120 d increased by 1100 in comparison.The quality of the cement-soil mixture should be comprehensively evaluated in accordance with the trimmed average of strength, coefficient of variation and rock quality designation （RQD） indicators of sampling ratio.
