Using a circular incremental step load and unload method, a set of rheological experiments were performed to study the viscoelasto-plastic properties of amphibolite in Jinchuan No.2 diggings under different environmen...Using a circular incremental step load and unload method, a set of rheological experiments were performed to study the viscoelasto-plastic properties of amphibolite in Jinchuan No.2 diggings under different environments. Based on the scientific analysis on rheological experimental data, the viscoelasto-plastic properties of amphibolite under different environments were studied. The results show that the instantaneous elastic modulus and viscoplastic properties of amphibolite are affected little, the viscoelastic properties of amphibolite are significantly affected. Based on the experimental results and characteristics of recovered rock specimen, a generalized Kelvin model was chosen to simulate rheological properties of amphibolites and key parameters were obtained. It is found that the creep deformation modulus E1 is significantly influenced by the water, while the instant elastic modulus E2 is not significantly affected. The discreteness of the viscosity coefficient η is large, the influence of water on η is not clear and needs to be further studied.展开更多
The dynamic mechanical properties and miscibility of an organic hybrid made from chlorinated polyethylene (CPE) and 2, 2'-methyIene-bis-( 4-methyl-6-cyclohexylphenol) ( ZKF ) are mainly discussed in this paper. It...The dynamic mechanical properties and miscibility of an organic hybrid made from chlorinated polyethylene (CPE) and 2, 2'-methyIene-bis-( 4-methyl-6-cyclohexylphenol) ( ZKF ) are mainly discussed in this paper. It is found that ZKF acts as an antiplasticizer in CPE matrix and has good miscibility even with large ratio in CPE /ZKF hybrids. The glass transition temperature of various CPE /ZKF hybrids determined by DSC give a good fit to Wood's equation. Bifunctional ZKF is supposed to improve the intermolecular force of CPE, and the improvement is developed when the ZKF content increases. On the other hand, the viscoelastic properties are highly improved with the addition of ZKF. TA and tanδ peak values increase when the ZKF content increase in the CPE /ZKF hybrids, the damping capacity has been improved during the glass transition of CPE /ZKF hybrids. In addition, the glass transition temperature shifts to room temperature from the low temperature with the continuous addition of ZKF to CPE.展开更多
为研究岩土材料非线性模糊随机损伤演变机理,建立广义非确定损伤力学模型,基于模糊随机双层数学覆盖下3种典型模糊损伤泛函,提出平面应变下服从随机β分布的各向异性初始模糊随机损伤场,及其广义FPDF(Fuzzy Probabilistic Density Funct...为研究岩土材料非线性模糊随机损伤演变机理,建立广义非确定损伤力学模型,基于模糊随机双层数学覆盖下3种典型模糊损伤泛函,提出平面应变下服从随机β分布的各向异性初始模糊随机损伤场,及其广义FPDF(Fuzzy Probabilistic Density Function)、FCDF(Fuzzy Cumulative Distribution Function)数学模型。并基于黏-弹-塑性模糊随机初始损伤应力场模型及损伤矢量临界值算法,推导了黏-弹-塑性模糊随机损伤本构模型,及模糊随机损伤变化率指数模型方程与数字特征算法。基于土方开挖损伤增益,探讨基坑工程损伤演变及广义可靠性,结果表明:模糊随机损伤模型可根据材料强度耗散对损伤分布调整,以反映细观粒子间的凝聚或断裂造成的复杂宏观硬化-屈服-破坏-重分布-愈合等力学性征。得到结论:阶段卸载导致场内损伤增益由单汇向多汇发展,且强度指标变异累加会诱发可靠指标削减,这些规律性认识对实现全面化、精确化分析研究有重要意义。展开更多
基金Project (10972238) supported by the National Natural Science Foundation of ChinaProject (2009bsxt061) supported by the Thesis Innovation Funds for the Central South University, ChinaProject (2009) supported by Hunan Administration of Work Safety Fund, China
文摘Using a circular incremental step load and unload method, a set of rheological experiments were performed to study the viscoelasto-plastic properties of amphibolite in Jinchuan No.2 diggings under different environments. Based on the scientific analysis on rheological experimental data, the viscoelasto-plastic properties of amphibolite under different environments were studied. The results show that the instantaneous elastic modulus and viscoplastic properties of amphibolite are affected little, the viscoelastic properties of amphibolite are significantly affected. Based on the experimental results and characteristics of recovered rock specimen, a generalized Kelvin model was chosen to simulate rheological properties of amphibolites and key parameters were obtained. It is found that the creep deformation modulus E1 is significantly influenced by the water, while the instant elastic modulus E2 is not significantly affected. The discreteness of the viscosity coefficient η is large, the influence of water on η is not clear and needs to be further studied.
文摘The dynamic mechanical properties and miscibility of an organic hybrid made from chlorinated polyethylene (CPE) and 2, 2'-methyIene-bis-( 4-methyl-6-cyclohexylphenol) ( ZKF ) are mainly discussed in this paper. It is found that ZKF acts as an antiplasticizer in CPE matrix and has good miscibility even with large ratio in CPE /ZKF hybrids. The glass transition temperature of various CPE /ZKF hybrids determined by DSC give a good fit to Wood's equation. Bifunctional ZKF is supposed to improve the intermolecular force of CPE, and the improvement is developed when the ZKF content increases. On the other hand, the viscoelastic properties are highly improved with the addition of ZKF. TA and tanδ peak values increase when the ZKF content increase in the CPE /ZKF hybrids, the damping capacity has been improved during the glass transition of CPE /ZKF hybrids. In addition, the glass transition temperature shifts to room temperature from the low temperature with the continuous addition of ZKF to CPE.
文摘为研究岩土材料非线性模糊随机损伤演变机理,建立广义非确定损伤力学模型,基于模糊随机双层数学覆盖下3种典型模糊损伤泛函,提出平面应变下服从随机β分布的各向异性初始模糊随机损伤场,及其广义FPDF(Fuzzy Probabilistic Density Function)、FCDF(Fuzzy Cumulative Distribution Function)数学模型。并基于黏-弹-塑性模糊随机初始损伤应力场模型及损伤矢量临界值算法,推导了黏-弹-塑性模糊随机损伤本构模型,及模糊随机损伤变化率指数模型方程与数字特征算法。基于土方开挖损伤增益,探讨基坑工程损伤演变及广义可靠性,结果表明:模糊随机损伤模型可根据材料强度耗散对损伤分布调整,以反映细观粒子间的凝聚或断裂造成的复杂宏观硬化-屈服-破坏-重分布-愈合等力学性征。得到结论:阶段卸载导致场内损伤增益由单汇向多汇发展,且强度指标变异累加会诱发可靠指标削减,这些规律性认识对实现全面化、精确化分析研究有重要意义。
