The research of the failure criterion and one-dimensional stress-strain relationship of deteriorated concrete were carried out. Based on the damage mechanics theory, the dsmage which reflects the alternation of intern...The research of the failure criterion and one-dimensional stress-strain relationship of deteriorated concrete were carried out. Based on the damage mechanics theory, the dsmage which reflects the alternation of internal state of material were introduced into the formula presented by Desayi and Krishman and the weighted twin-shear strength theory. As a nondestructive examination method in common use, the ultrasonic technique was adopted in the study, and the ultrasonic velocity was used to establish the damage variable. After that, the failure criterion and one-dimensional stress-strain relationship for deteriorated concrete were obtained. Eventually, tests were carried out to study the evolution laws on the damage. The results show that the more freezing and thawing cycles are, the more apparently the failure surface shrinks. Meanwhile, the comparison between theoretical data and experimental data verifies tile rationality of tile damage-based one-dimensional stress-strain relationship proposed.展开更多
对于均匀、各向同性、幂律硬化的金属材料,以锥形端头小冲杆对试样圆面中心法向施加压载荷,提出基于能量密度等效的,用于描述试样几何尺寸、材料本构关系参数、载荷和位移之间关系的锥-小冲杆试验(cone small punch test,C-SPT)载荷-位...对于均匀、各向同性、幂律硬化的金属材料,以锥形端头小冲杆对试样圆面中心法向施加压载荷,提出基于能量密度等效的,用于描述试样几何尺寸、材料本构关系参数、载荷和位移之间关系的锥-小冲杆试验(cone small punch test,C-SPT)载荷-位移模型,并提出获取材料应力-应变关系和力学性能指标的锥-小冲杆试验新方法。通过有限元分析不同弹性模量、屈服强度和硬化指数的100种预设材料进行新方法的数值验证,及对3种金属材料完成CSPT。结果表明:由新方法预测的应力-应变关系与有限元分析预设曲线和传统单轴拉伸试验结果吻合良好,此外,由新方法获得的抗拉强度与单轴拉伸试验结果误差较小。展开更多
为了探究单轴受压下石粉-钢渣混凝土的本构关系,根据正交试验方案配制了不同掺量钢渣砂(30%、40%、50%)、钢渣石(30%、40%、50%)、石粉(0%、7.5%、15%)的石粉-钢渣混凝土,对石粉-钢渣混凝土的应力-应变关系进行了实验研究,建立了单轴受...为了探究单轴受压下石粉-钢渣混凝土的本构关系,根据正交试验方案配制了不同掺量钢渣砂(30%、40%、50%)、钢渣石(30%、40%、50%)、石粉(0%、7.5%、15%)的石粉-钢渣混凝土,对石粉-钢渣混凝土的应力-应变关系进行了实验研究,建立了单轴受压下石粉-钢渣混凝土的本构关系模型。实验结果表明:当受到单轴压力时,石粉-钢渣混凝土的破坏模式与普通混凝土相似,表现出斜剪切的特征。石粉-钢渣混凝土峰值应力、峰值应变及弹性模量随着钢渣骨料掺量的增加而提高。为了更好地模拟无量纲应力-应变曲线,本工作采用了Carreira and Chu模型的上升段和过镇海模型的下降段进行了分段拟合。结果表明,实验曲线与分段模型曲线吻合较好。展开更多
文摘The research of the failure criterion and one-dimensional stress-strain relationship of deteriorated concrete were carried out. Based on the damage mechanics theory, the dsmage which reflects the alternation of internal state of material were introduced into the formula presented by Desayi and Krishman and the weighted twin-shear strength theory. As a nondestructive examination method in common use, the ultrasonic technique was adopted in the study, and the ultrasonic velocity was used to establish the damage variable. After that, the failure criterion and one-dimensional stress-strain relationship for deteriorated concrete were obtained. Eventually, tests were carried out to study the evolution laws on the damage. The results show that the more freezing and thawing cycles are, the more apparently the failure surface shrinks. Meanwhile, the comparison between theoretical data and experimental data verifies tile rationality of tile damage-based one-dimensional stress-strain relationship proposed.
文摘对于均匀、各向同性、幂律硬化的金属材料,以锥形端头小冲杆对试样圆面中心法向施加压载荷,提出基于能量密度等效的,用于描述试样几何尺寸、材料本构关系参数、载荷和位移之间关系的锥-小冲杆试验(cone small punch test,C-SPT)载荷-位移模型,并提出获取材料应力-应变关系和力学性能指标的锥-小冲杆试验新方法。通过有限元分析不同弹性模量、屈服强度和硬化指数的100种预设材料进行新方法的数值验证,及对3种金属材料完成CSPT。结果表明:由新方法预测的应力-应变关系与有限元分析预设曲线和传统单轴拉伸试验结果吻合良好,此外,由新方法获得的抗拉强度与单轴拉伸试验结果误差较小。
文摘为了探究单轴受压下石粉-钢渣混凝土的本构关系,根据正交试验方案配制了不同掺量钢渣砂(30%、40%、50%)、钢渣石(30%、40%、50%)、石粉(0%、7.5%、15%)的石粉-钢渣混凝土,对石粉-钢渣混凝土的应力-应变关系进行了实验研究,建立了单轴受压下石粉-钢渣混凝土的本构关系模型。实验结果表明:当受到单轴压力时,石粉-钢渣混凝土的破坏模式与普通混凝土相似,表现出斜剪切的特征。石粉-钢渣混凝土峰值应力、峰值应变及弹性模量随着钢渣骨料掺量的增加而提高。为了更好地模拟无量纲应力-应变曲线,本工作采用了Carreira and Chu模型的上升段和过镇海模型的下降段进行了分段拟合。结果表明,实验曲线与分段模型曲线吻合较好。
