scholarly journals Talc under tension and compression: Spinodal instability, elasticity, and structure

2002 ◽  
Vol 107 (B12) ◽  
pp. ECV 2-1-ECV 2-10 ◽  
Author(s):  
Lars Stixrude
Keyword(s):  
Tension And Compression ◽  
Spinodal Instability

Methodology of studying the mechanical properties of composite materials (reinforced concrete)

2018 ◽  
Vol 84 (12) ◽  
pp. 61-67
Author(s):  
V. A. Eryshev
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Experimental Studies ◽  
Analytical Relationship ◽  
Hardened Concrete ◽  
Deformation Model ◽  
Joint Work ◽  
Concrete Shrinkage ◽  
Axial Tension ◽  
Tension And Compression

The mechanical properties of a complex composite material formed by steel and hardened concrete, are studied. A technique of operative quality control of new credible concrete and reinforcement, both in laboratory and field conditions is developed for determination of the strength and strain characteristics of materials, as well as cohesion forces determining their joint operation under load. The design of the mobile unit is presented. The unit provides a possibility of changing the direction of loading and testing the reinforced element of the given shape both for tension and compression. Moreover, the nomenclature of testing equipment and the number of molds for manufacturing concrete samples substantially decrease. Using the values of forcing resulting in concrete cracking when the joint work of concrete and reinforcement is disrupted the values of the inherent stresses and strains attributed to the concrete shrinkage are determined. An analytical relationship between the forces and deformations of the reinforced concrete sample with central reinforcement is derived for axial tension and compression, with allowance for strains and stresses in the reinforcement and concrete resulted from concrete shrinkage. The results of experimental studies are presented, including tension diagrams and diagrams of developing axial deformations with an increase in the load under the central loading of the reinforced elements. A methodology of accounting for stresses and deformations resulted from concrete shrinkage is developed. The applicability of the derived analytical relationships between stresses and deformations on the material diagrams to calculations of the reinforced concrete structures in the framework of the deformation model is estimated.

Modelling the asymmetric tension–compression properties of additively manufactured alloys using continuum damage mechanics

2021 ◽  
pp. 146442072110134
Author(s):  
A Nayebi ◽  
H Rokhgireh ◽  
M Araghi ◽  
M Mohammadi
Keyword(s):  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Element Model ◽  
Continuum Damage ◽  
Compression Tests ◽  
Compression Properties ◽  
Mechanics Model ◽  
Stress Components ◽  
Tension And Compression ◽  
Closure Effect

Additively manufactured parts often comprise internal porosities due to the manufacturing process, which needs to be considered in modelling their mechanical behaviour. It was experimentally shown that additively manufactured parts’ tensile and compressive mechanical properties are different for various metallic alloys. In this study, isotropic continuum damage mechanics is used to model additively manufactured alloys’ tension and compression behaviours. Compressive stress components can shrink discontinuities present in additively manufactured alloys. Therefore, the crack closure effect was employed to describe different behaviours during uniaxial tension and compression tests. A finite element model embedded in an ABAQUS’s UMAT format was developed to account for the isotropic continuum damage mechanics model. The numerical results of tension and compression tests were compared with experimental observations for additively manufactured maraging steel, AlSi10Mg and Ti-6Al-4V. Stress–strain curves in tension and compression of these alloys were obtained using the continuum damage mechanics model and compared well with the experimental results.

scholarly journals A General Temperature-Dependent Stress–Strain Constitutive Model for Polymer-Bonded Composite Materials

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1393
Author(s):  
Xiaochang Duan ◽  
Hongwei Yuan ◽  
Wei Tang ◽  
Jingjing He ◽  
Xuefei Guan
Keyword(s):  
Composite Materials ◽  
Constitutive Model ◽  
Model Parameters ◽  
Temperature Dependent ◽  
Stress Strain ◽  
Proposed Model ◽  
Single Temperature ◽  
Testing Data ◽  
Bonded Composite ◽  
Tension And Compression

This study develops a general temperature-dependent stress–strain constitutive model for polymer-bonded composite materials, allowing for the prediction of deformation behaviors under tension and compression in the testing temperature range. Laboratory testing of the material specimens in uniaxial tension and compression at multiple temperatures ranging from −40 ∘C to 75 ∘C is performed. The testing data reveal that the stress–strain response can be divided into two general regimes, namely, a short elastic part followed by the plastic part; therefore, the Ramberg–Osgood relationship is proposed to build the stress–strain constitutive model at a single temperature. By correlating the model parameters with the corresponding temperature using a response surface, a general temperature-dependent stress–strain constitutive model is established. The effectiveness and accuracy of the proposed model are validated using several independent sets of testing data and third-party data. The performance of the proposed model is compared with an existing reference model. The validation and comparison results show that the proposed model has a lower number of parameters and yields smaller relative errors. The proposed constitutive model is further implemented as a user material routine in a finite element package. A simple structural example using the developed user material is presented and its accuracy is verified.

scholarly journals Influence of Cold Rotary Swaging on Microstructure and Uniaxial Mechanical Behavior in Alloy 718

2021 ◽  
Author(s):  
Alexander Klumpp ◽  
Alexander Kauffmann ◽  
Sascha Seils ◽  
Stefan Dietrich ◽  
Volker Schulze
Keyword(s):  
Mechanical Behavior ◽  
Electron Backscatter Diffraction ◽  
Moderate Increase ◽  
Alloy 718 ◽  
Pronounced Increase ◽  
Rotary Swaging ◽  
Elastic Range ◽  
Nickel Based Superalloy ◽  
Tempering Treatment ◽  
Tension And Compression

AbstractIn this study, the influence of cold rotary swaging on microstructure and mechanical properties of the precipitation-strengthened nickel-based superalloy 718 (Alloy 718) was investigated. The initial stages of work-hardening were characterized by means of microhardness, electron backscatter diffraction (EBSD), and X-ray diffraction (XRD) analyses. Furthermore, attention was devoted to the mechanical behavior at ambient and elevated temperature (550 °C) in uniaxial tension and compression. Rotary swaging to different true strains of maximum $$\varphi = 0.91$$ φ = 0.91 caused a moderate increase of microhardness and enhanced markedly the load-bearing capacity in tension, giving rise to yield strength beyond 2000 MPa. The mechanical strength $$R_{p0.2}$$ R p 0.2 in tension subsequent to rotary swaging perfectly correlates with increasing dislocation density $$\rho $$ ρ estimated from XRD in the form of a Taylor-like relationship $$R_{p0.2} \propto \sqrt{\rho }$$ R p 0.2 ∝ ρ . In compression, transient stress–strain evolution without the occurrence of a clear elastic range and distinct yield phenomenon was observed. Restoration of the elastic range, accompanied by a pronounced increase of microhardness, was obtained by a post-swaging tempering treatment at 600 °C.

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

Materials ◽  
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.

Tension and Compression Behavior of Pre-Stressed Steel Strands at High Strain Rate

2011 ◽  
Vol 82 ◽  
pp. 154-159 ◽  
Author(s):  
Anatoly M. Bragov ◽  
Ezio Cadoni ◽  
Alexandr Yu. Konstantinov ◽  
Andrey K. Lomunov
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
High Strength ◽  
Gauge Length ◽  
Hopkinson Pressure Bar ◽  
Dog Bone ◽  
Tension And Compression ◽  
Set Up

In this paper is described the mechanical characterization at high strain rate of the high strength steel usually adopted for strands. The experimental set-up used for high strain rates testing: in tension and compression was the Split Hopkinson Pressure Bar installed in the Laboratory of Dynamic Investigation of Materials in Nizhny Novgorod. The high strain rate data in tension was obtained with dog-bone shaped specimens of 3mm in diameter and 5mm of gauge length. The specimens were screwed between incident and transmitter bars. The specimens used in compression was a cylinder of 3mm in diameter and 5mm in length. The enhancement of the mechanical properties is quite limited compared the usual reinforcing steels.

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