scholarly journals Global Mechanical Behavior Characterization of Uniaxially Loaded Rock Specimen Based on Its Structural Evolution

2020 ◽  
Vol 10 (21) ◽  
pp. 7647
Author(s):  
Tongzhen Xing ◽  
Haibin Zhu ◽  
Guangyan Liu ◽  
Yimin Song ◽  
Shaopeng Ma
Keyword(s):  
Mechanical Behavior ◽  
Uniaxial Compression ◽  
Structural Model ◽  
Rock Specimen ◽  
Structural Evolution ◽  
Image Correlation ◽  
Evolution Process ◽  
Deformation Localization ◽  
Characterization Model ◽  
Rock Structure

Characterizing global mechanical behavior accurately is important for a detailed understanding of the deformation mechanism of rock material. In this paper, a new characterization model of the global mechanical behavior of rock is proposed, based on the structural characteristics of rock deformation. Uniaxial compression tests were carried out using the digital image correlation method and acoustic emission to obtain the interrelationship between mechanical behavior and deformation evolution. The test results show that the appearance of deformation localization leads to non-linear evolution of global mechanical behavior in a rock specimen. Further, due to the gradual evolution of deformation localization bands, the rock specimen evolves from a complete whole to a rock structure with a “weak interlayer”. Thus, the global mechanical behavior of the rock specimen depends heavily on the structural evolution process, especially when close to failure. A simplified characterization model was established according to the deformation process. The finite element method was used to verify the rationality of the proposed structural model. The verification result showed that under uniaxial compression, the structural model can reproduce the global mechanical behavior evolution process of the rock specimen.

scholarly journals Mechanical behavior of Ti-6Al-4V lattice-walled tubes under uniaxial compression

2021 ◽  
Author(s):  
Gen-zhu Feng ◽  
Jing Wang ◽  
Xin-yuan Li ◽  
Li-jun Xiao ◽  
Wei-dong Song
Keyword(s):  
Mechanical Behavior ◽  
Uniaxial Compression

scholarly journals Multi-Scale Digital Image Correlation Analysis of In Situ Deformation of Open-Cell UHMWPE Foam

2020 ◽  
Author(s):  
Eugene S. Statnik ◽  
Codrutza Dragu ◽  
Cyril Besnard ◽  
Alexander J.G. Lunt ◽  
Alexey I. Salimon ◽  
...  
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
High Performance ◽  
Structural Evolution ◽  
Image Correlation ◽  
Deformation Bands ◽  
Open Cell ◽  
Polyether Ether Ketone ◽  
Structural Levels

Porous ultra-high molecular weight polyethylene (UHMWPE) is a high performance bioinert polymer used in cranio-facial reconstructive surgery in procedures where relatively low mechanical stresses arise. As an alternative to much stiffer and costly polyether-ether-ketone (PEEK) polymer, UHMWPE finds further wide application in hierarchically structured hybrids for advanced implants mimicking cartilage, cortical and trabecular bone tissues within a single component. The mechanical behaviour of open-cell UHMWPE sponges obtained through sacrificial desalination of hot compression-moulded UHMWPE-NaCl powder mixtures shows a complex dependence on the fabrication parameters and microstructural features. In particular, similarly to other porous media it displays significant inhomogeneity of strain that readily localises within deformation bands that govern the overall response. In this article, we report advances in the development of accurate experimental techniques for operando studies of the structure-performance relationship applied to the porous UHMWPE medium with pore sizes of about 250 µm that are most well-suited for live cell proliferation and fast vascularization of implants. Samples of UHMWPE sponges were subjected to in situ compression using a micromechanical testing device within Scanning Electron Microscope (SEM) chamber, allowing the acquisition of high-resolution image sequences for Digital Image Correlation (DIC) analysis. Special masking and image processing algorithms were developed and applied to reveal the evolution of pore size and aspect ratio. Key structural evolution and deformation localisation phenomena were identified at both macro- and micro-structural levels in the elastic and plastic regimes. The motion of pore walls was quantitatively described, and the presence and influence of strain localisation zones were revealed and analysed using DIC technique.

Mechanical Behavior of 2D C/SiC Composites at Elevated Temperatures under Uniaxial Compression

2011 ◽  
Vol 462-463 ◽  
pp. 1-6 ◽  
Author(s):  
Tao Suo ◽  
Yu Long Li ◽  
Ming Shuang Liu
Keyword(s):  
Compressive Strength ◽  
High Temperature ◽  
Carbon Fiber ◽  
Mechanical Behavior ◽  
Uniaxial Compression ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Carbon Matrix ◽  
Structural Applications ◽  
Sic Composites

As Carbon-fiber-reinforced SiC-matrix (C/SiC) composites are widely used in high-temperature structural applications, its mechanical behavior at high temperature is important for the reliability of structures. In this paper, mechanical behavior of a kind of 2D C/SiC composite was investigated at temperatures ranging from room temperature (20C) to 600C under quasi-static and dynamic uniaxial compression. The results show the composite has excellent high temperature mechanical properties at the tested temperature range. Catastrophic brittle failure is not observed for the specimens tested at different strain rates. The compressive strength of the composite deceases only 10% at 600C if compared with that at room temperature. It is proposed that the decrease of compressive strength of the 2D C/SiC composite at high temperature is influenced mainly by release of thermal residual stresses in the reinforced carbon fiber and silicon carbon matrix and oxidation of the composite in high temperature atmosphere.

Mechanical Behavior of Aluminum Foam Under Uniaxial Compression

2006 ◽  
pp. 73-82
Author(s):  
B. Kriszt ◽  
B. Foroughi ◽  
A. Kottar ◽  
H.P. Degischer
Keyword(s):  
Mechanical Behavior ◽  
Uniaxial Compression ◽  
Aluminum Foam

Shear band propagation in honeycombs: numerical and experimental

2018 ◽  
Vol 24 (2) ◽  
pp. 477-484
Author(s):  
Hossein Goodarzi Hosseinabadi ◽  
Reza Bagheri ◽  
Volker Altstädt
Keyword(s):  
Finite Element ◽  
Shear Band ◽  
Energy Absorption ◽  
Image Correlation ◽  
Correlation Technique ◽  
Deformation Localization ◽  
Content Type ◽  
Fused Deposition ◽  
Absorption Potential ◽  
3D Printed

Purpose Hexagonal honeycombs with meso-metric cell size show excellent load bearing and energy absorption potential, which make them attractive in many applications. However, owing to their bend-dominated structure, honeycombs are susceptible to deformation localization. The purpose of this study is to provide insight about shear band propagation in struts of 3D-printed honeycombs and its relation to the achieved macroscopic mechanical behavior. Design/methodology/approach Hexagonal honeycombs and unit cell models are 3D-printed by fused deposition modeling (FDM). The samples are exposed to compression loading and digital image correlation technique and finite element analyses are incorporated. Findings It is found that the strain contours, which are obtained by finite element, are in agreement with experimental measurements made by DIC. In addition, three stages of shear band propagation in struts of 3D-printed honeycombs are illustrated. Then the correlation between shear band propagation stages and the achieved macroscopic mechanical responses is discussed in detail. Originality/value For the first time, a hierarchical activation of different modes of shear band propagation in struts of a 3D-printed honeycomb is reported. This information can be of use for designing a new generation of honeycombs with tailor-made localization and energy absorption potential.

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