This paper developed a statistical damage constitutive model for deep rock by considering the effects of external load and thermal treatment temperature based on the distortion energy.The model parameters were determi...This paper developed a statistical damage constitutive model for deep rock by considering the effects of external load and thermal treatment temperature based on the distortion energy.The model parameters were determined through the extremum features of stress−strain curve.Subsequently,the model predictions were compared with experimental results of marble samples.It is found that when the treatment temperature rises,the coupling damage evolution curve shows an S-shape and the slope of ascending branch gradually decreases during the coupling damage evolution process.At a constant temperature,confining pressure can suppress the expansion of micro-fractures.As the confining pressure increases the rock exhibits ductility characteristics,and the shape of coupling damage curve changes from an S-shape into a quasi-parabolic shape.This model can well characterize the influence of high temperature on the mechanical properties of deep rock and its brittleness-ductility transition characteristics under confining pressure.Also,it is suitable for sandstone and granite,especially in predicting the pre-peak stage and peak stress of stress−strain curve under the coupling action of confining pressure and high temperature.The relevant results can provide a reference for further research on the constitutive relationship of rock-like materials and their engineering applications.展开更多
文摘为了更合理地动态预测桥梁耦合极值应力,将历史监测极值应力数据视为多阶模态响应耦合的多分量信号,并结合Hilbert信号分解以及Hilbert平方解调技术(Hilbert Square Demodulation,HSD)在多分量信号解调方面的优势,提出了预测桥梁极值应力的贝叶斯Hilbert动态线性模型(Bayesian Hilbert Dynamic Linear Model,BHDLM)。利用Hilbert信号分解技术实现对监测极值应力的解耦,并基于HSD建立了各阶应力响应的Hilbert动态线性模型(Hilbert Dynamic Linear Model,HDLM);结合贝叶斯方法以及单分量极值应力对HDLM进行概率递推,实现了对单分量桥梁极值应力的动态预测,进而可得桥梁耦合极值应力的动态预测;利用在役桥梁的监测数据对本文所提模型的有效性进行了验证。结果表明:利用解耦得到的单分量极值应力数据建立的HDLM过程简单,并能很好地反映出监测数据的周期性、随机性等特点。结合贝叶斯方法,可以有效地对桥梁极值应力进行动态预测。
基金Project(11272119)supported by the National Natural Science Foundation of China。
文摘This paper developed a statistical damage constitutive model for deep rock by considering the effects of external load and thermal treatment temperature based on the distortion energy.The model parameters were determined through the extremum features of stress−strain curve.Subsequently,the model predictions were compared with experimental results of marble samples.It is found that when the treatment temperature rises,the coupling damage evolution curve shows an S-shape and the slope of ascending branch gradually decreases during the coupling damage evolution process.At a constant temperature,confining pressure can suppress the expansion of micro-fractures.As the confining pressure increases the rock exhibits ductility characteristics,and the shape of coupling damage curve changes from an S-shape into a quasi-parabolic shape.This model can well characterize the influence of high temperature on the mechanical properties of deep rock and its brittleness-ductility transition characteristics under confining pressure.Also,it is suitable for sandstone and granite,especially in predicting the pre-peak stage and peak stress of stress−strain curve under the coupling action of confining pressure and high temperature.The relevant results can provide a reference for further research on the constitutive relationship of rock-like materials and their engineering applications.
