摘要
抗剪强度和剪切变形是砼的基本力学性能,又是强度理论研究和有限元分析的重要数据。本文用有限元方法分析了现有几种抗剪试件的应力状态,论证了破坏剪切面上的剪应力分布不均匀,且存在数倍于剪应力的正应力,因而不能给出准确的砼抗剪强度值。作者设计了四点受力等高变宽梁的抗剪试验方法,试件跨中剪切面接近纯剪状态,故给出的抗剪强度较为可靠。按此方法进行了不同强度(f_cu=17～64MPa)砼的试验,测定了抗剪强度和峰值应变,研究了它们与抗拉、抗压强度的关系,建议了剪应力-应变曲线方程,以及剪切模量的计算式。
Shear strength and shear strain are the basic properties in mechanics of concrete. They also serve as important data for finite element and failure criterion research on concrete. In this paper, the finite element program SAP-5 has been used to analyze the stress states of specimens with different forms in previous tests. It has been demonstrated that the shear stresses are not uniformly distributed on the critical section and the normal stresses existing on the section are several times as high as that of the shear stress. Therefore, such tests can hardly provide accurate shear strength values. This paper presents a four points loaded beam specimen with uniform depth and varying width, by which the stress state in the centre span section will approach pure shear stress, and the shear strength of concrete thus obtained will be comparatively accurate.The cubic strength of concrete specimens ranges from 17 to 64 Mpa. The shear strength and strain at peak stress are measured and their relations to compressive and tensile strength are analyzed. The shear stress-strain curves are measured during testing, and the expressions for computing these curves and the shear modulus of concrete are suggested.
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
1992年第5期17-24,共8页
Journal of Building Structures
基金
国家教育委员会博士点基金
