An elastoplastic constitutive model based on the Modified Cam Clay(MCC)model is developed to describe the mechanical behaviour of soils cemented via microbially induced calcite precipitation(MICP).It considers the inc...An elastoplastic constitutive model based on the Modified Cam Clay(MCC)model is developed to describe the mechanical behaviour of soils cemented via microbially induced calcite precipitation(MICP).It considers the increase of the elastic stiffness,the change of the yield surface due to MICP cementation and the degradation of calcium carbonate bonds during shearing.Specifically,to capture the typical contraction-dilation transition in MICP soils,the original volumetric hardening rule in the MCC model is modified to a combined deviatoric and volumetric hardening rule.The model could reproduce a series of drained triaxial tests on MICP-treated soils with different calcium carbonate contents.Further,we carry out a parametric study and observe numerical instability in some cases.In combination with an analytical analysis,our numerical modelling has identified the benefits and limitations of using MCCbased models in the simulation of MICP-cemented soils,leading to suggestions for further model development.展开更多
【目的】采用CAD/CAM标准测试模型评价四种不同临时冠粘结剂的粘结强度。【方法】参照因牙周病拔除的完整上颌中切牙CAD/CAM40副上颌中切牙的树脂测试模型(包括预备体和带固位孔的临时冠),分为4组(氧化锌组、玻璃离子体水门汀组、磷酸...【目的】采用CAD/CAM标准测试模型评价四种不同临时冠粘结剂的粘结强度。【方法】参照因牙周病拔除的完整上颌中切牙CAD/CAM40副上颌中切牙的树脂测试模型(包括预备体和带固位孔的临时冠),分为4组(氧化锌组、玻璃离子体水门汀组、磷酸锌水门汀组和Tempo Cem NE组),每组10副模型,每组分别采用4种不同的临时冠粘结剂进行粘结。采用MTS力学测试机对每一副模型以1mm/min的速度进行粘结强度测试,测出并记录每组每一副模型的粘结强度。【结果】4组的粘结强度分别为氧化锌组(37.48±4.92)N、玻璃离子体水门汀组(52.13±9.28)N、磷酸锌水门汀组(36.16±6.13)N、Tempo Cem NE组(46.21±6.70)N;玻璃离子体水门汀组和Tempo Cem NE组的粘结强度大于氧化锌组和磷酸锌水门汀组,差异具有统计学意义(P<0.05)。【结论】采用CAD/CAM上颌中切牙的标准测试模型进行4种临时冠粘结剂粘结强度的测试,实验结果认为玻璃离子体水门汀和Tempo Cem NE的粘结效果较好,值得临床广泛应用。展开更多
基金funded by the German Research Foundation(DFG)(Grant No.NA 330/20e1).
文摘An elastoplastic constitutive model based on the Modified Cam Clay(MCC)model is developed to describe the mechanical behaviour of soils cemented via microbially induced calcite precipitation(MICP).It considers the increase of the elastic stiffness,the change of the yield surface due to MICP cementation and the degradation of calcium carbonate bonds during shearing.Specifically,to capture the typical contraction-dilation transition in MICP soils,the original volumetric hardening rule in the MCC model is modified to a combined deviatoric and volumetric hardening rule.The model could reproduce a series of drained triaxial tests on MICP-treated soils with different calcium carbonate contents.Further,we carry out a parametric study and observe numerical instability in some cases.In combination with an analytical analysis,our numerical modelling has identified the benefits and limitations of using MCCbased models in the simulation of MICP-cemented soils,leading to suggestions for further model development.
文摘【目的】采用CAD/CAM标准测试模型评价四种不同临时冠粘结剂的粘结强度。【方法】参照因牙周病拔除的完整上颌中切牙CAD/CAM40副上颌中切牙的树脂测试模型(包括预备体和带固位孔的临时冠),分为4组(氧化锌组、玻璃离子体水门汀组、磷酸锌水门汀组和Tempo Cem NE组),每组10副模型,每组分别采用4种不同的临时冠粘结剂进行粘结。采用MTS力学测试机对每一副模型以1mm/min的速度进行粘结强度测试,测出并记录每组每一副模型的粘结强度。【结果】4组的粘结强度分别为氧化锌组(37.48±4.92)N、玻璃离子体水门汀组(52.13±9.28)N、磷酸锌水门汀组(36.16±6.13)N、Tempo Cem NE组(46.21±6.70)N;玻璃离子体水门汀组和Tempo Cem NE组的粘结强度大于氧化锌组和磷酸锌水门汀组,差异具有统计学意义(P<0.05)。【结论】采用CAD/CAM上颌中切牙的标准测试模型进行4种临时冠粘结剂粘结强度的测试,实验结果认为玻璃离子体水门汀和Tempo Cem NE的粘结效果较好,值得临床广泛应用。
