An Effect of the Slope Layer in Sheet Sample on a Strength for Negative Coefficient of a Biaxial Loading Factor of a Sample

In this work, a new damage model for concrete is proposed with an extension of the stress decomposition (limited to biaxial cases), to capture shear damage due to the opposite signed principal stresses. To extract the pure shear stress, the assumption is made that one component of the shear stress is a minimum absolute of the two principal stresses. The opposite signed principal stresses are decomposed into shear stress and uniaxial tensile/compressive stress. A local model is implemented in Abaqus UMAT and it is further extended to a non-local model by utilization of the gradient theory. The concept of three length scales (tension, compression, and shear) is kept the same as the recently proposed nonlocal damage model by the authors. The nonlocal model is implemented in the Abaqus UEL-UMAT subroutine with an eight-node quadrilateral user-defined element, having five degrees of freedom at corner nodes (displacement in X/Y direction and tensile/compressive and shear nonlocal equivalent strain) and two degrees of freedom at internal nodes. Some examples of a local model including uniaxial and biaxial loading are addressed. Also, five examples of mixed crack mode and mode-I cracking are presented to comprehensively show the performance of this model.

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Characterizations of material constraint effect for creep crack in center weldment under biaxial loading

International Journal of Fracture ◽

10.1007/s10704-021-00563-6 ◽

2021 ◽

Author(s):

Yanwei Dai ◽

Fei Qin ◽

Yinghua Liu ◽

Filippo Berto ◽

Haofeng Chen

Keyword(s):

Biaxial Loading ◽

Constraint Effect ◽

Creep Crack

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The Effect of Void Arrangement on the Pattern Transformation of Porous Soft Solids under Biaxial Loading

Materials ◽

10.3390/ma14051205 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1205

Author(s):

Hai Qiu ◽

Ying Li ◽

Tianfu Guo ◽

Shan Tang ◽

Zhaoqian Xie ◽

...

Keyword(s):

Biaxial Loading ◽

Tensile Deformation ◽

Biaxial Stress ◽

Porous Solids ◽

Biaxial Compression ◽

Structural Topology ◽

Soft Solids ◽

Tension And Compression ◽

Inclined Angle ◽

Pattern Transformation

Structural topology and loading condition have important influences on the mechanical behaviors of porous soft solids. The porous solids are usually set to be under uniaxial tension or compression. Only a few studies have considered the biaxial loads, especially the combined loads of tension and compression. In this study, porous soft solids with oblique and square lattices of circular voids under biaxial loadings were studied through integrated experiments and numerical simulations. For the soft solids with oblique lattices of circular voids, we found a new pattern transformation under biaxial compression, which has alternating elliptic voids with an inclined angle. This kind of pattern transformation is rarely reported under uniaxial compression. Introducing tensile deformation in one direction can hamper this kind of pattern transformation under biaxial loading. For the soft solids with square lattices of voids, the number of voids cannot change their deformation behaviors qualitatively, but quantitatively. In general, our present results demonstrate that void morphology and biaxial loading can be harnessed to tune the pattern transformations of porous soft solids under large deformation. This discovery offers a new avenue for designing the void morphology of soft solids for controlling their deformation patterns under a specific biaxial stress-state.

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