高韧性水泥基复合材料拉伸和弯曲性能的相关性

Correlation of tensile and flexural behaviors of high toughness cementitious composites

高韧性水泥基复合(HTCC)材料的拉伸应力-应变关系能够反映其力学性能,而简单的线性模型无法不能准确地分析其力学性能。为更准确地分析HTCC材料的力学性能,提出可以体现其应变硬化和软化行为的四线型拉伸本构。基于该本构模型,推导出矩形截面构件的弯矩-曲率响应的理论解。利用弯矩面积法计算出三点弯曲和四点弯曲试验构件的跨中挠度,得到HTCC材料拉伸和弯曲性能之间的关系。利用该模型对HTCC材料的弯曲性能进行模拟,并对比文献中的数据验证该模型的准确性。通过参数分析,研究HTCC材料拉伸本构参数的变化对其弯曲性能的影响。该模型能够准确预测HTCC材料的拉伸本构参数或弯曲力学性能,为HTCC材料在矩形截面构件设计中的应用提供技术支撑。

The mechanical performance of high toughness cementitious composite(HTCC)can be indicated by its tensile stress-strain response.Furthermore,the simplified linear models cannot accurately analyze the mechanical performance of the HTCC materials.To analyze the mechanical performance of the HTCC materials with high accuracy,a four-stage linear constitutive model was proposed to represent the strain hardening and softening behaviors of the HTCC materials.Based on the proposed constitutive model,the theoretical solution for the moment-curvature response of the components with rectangular cross-section was derived.The mid-span deflections of the components in the three-point and four-point bending tests were calculated by using the method of bending moment area,and the correlation between the tensile and flexural performances of the HTCC materials was obtained.The analytical model was used to simulate the flexural behavior of HTCC material,and the accuracy of the model was verified through the comparison with the experimental data in the literature.The influence of the tensile constitutive parameters on the flexural behavior of the HTCC materials was then analyzed through the parameter analysis.Based on the analysis results,it is disclosed that the analytical model can accurately evaluate the parameters of the tensile constitutive model or the flexural mechanical behaviors of the HTCC materials,and provide technical support for the flexural performance design of the rectangular components made of HTCC materials.