On the effect of geometrical fiber arrangement on damage initiation in CFRPs under transverse tension and compression

2021 ◽  
pp. 114360
Author(s):  
Miguel Marco ◽  
Eugenio Giner ◽  
María Henar Miguélez ◽  
David González
Keyword(s):  
Damage Initiation ◽  
Transverse Tension ◽  
Fiber Arrangement ◽  
Tension And Compression

Three-dimensional elastic-plastic damage constitutive model of wood

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Lipeng Zhang ◽  
Qifang Xie ◽  
Baozhuang Zhang ◽  
Long Wang ◽  
Jitao Yao
Keyword(s):  
Constitutive Model ◽  
Damage Mechanics ◽  
Euler Method ◽  
Isotropic Hardening ◽  
Damage Initiation ◽  
Elastic Plastic ◽  
Plastic Damage ◽  
Backward Euler ◽  
Tension And Compression ◽  
Damage Constitutive Model

AbstractA 3D combined elastic-plastic damage constitutive model for wood is proposed within the theoretical framework of classical plasticity and continuum damage mechanics (CDM). The model is able to describe the various behavior of wood under loading, including the orthotropic elasticity, strengths inequality under tension and compression in each orthotropic direction, ductile softening under longitudinal compression, brittle failure under transverse tension, and parallel shearing, densification hardening under transverse compression. Hoffman criterion and a set of eight separate failure criteria were used to define wood yielding and damage initiation, respectively. Isotropic hardening was assumed after yielding and defined by an exponential type function. The constitutive model was implicitly discretized using backward Euler method, solved through the return mapping algorithm and implemented into ABAQUS through the user-defined material subroutine (UMAT). The proposed model was firstly verified by material property tests considering different stress states: monotonic and repeated tension and compression (in both parallel and perpendicular-to-grain directions), parallel-to-grain shearing, and the interactions between perpendicular-to-grain compression/tension and parallel-to-grain shearing, etc. Mechanical behavior of typical structural elements was further simulated to validate the proposed constitutive model.

scholarly journals Effect of Strain Rate on the Transverse Tension and Compression Behavior of a Unidirectional Non-Crimp Fabric Carbon Fiber/Snap-Cure Epoxy Composite

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7314
Author(s):  
Khizar Rouf ◽  
Aaditya Suratkar ◽  
Jose Imbert-Boyd ◽  
Jeffrey Wood ◽  
Michael Worswick ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Fracture Surface ◽  
Strain Rate ◽  
Epoxy Composite ◽  
Strain Rates ◽  
Transverse Compression ◽  
Compression Tests ◽  
Rate Dependent ◽  
Transverse Tension ◽  
Tension And Compression

The strain rate-dependent behavior of a unidirectional non-crimp fabric (UD-NCF) carbon fiber/snap-cure epoxy composite loaded along the transverse direction under quasi-static and dynamic conditions was characterized. Transverse tension and compression tests at quasi-static and intermediate strain rates were performed using hydraulic testing machines, while a split Hopkinson pressure bar (SHPB) apparatus was used for transverse compression tests at high strain rates. A pulse shaper was used on the SHPB apparatus to ensure dynamic equilibrium was achieved and that the test specimens deformed homogenously with a nearly constant strain rate. The transverse tensile strength at a strain rate of 16 s−1 increased by 16% when compared to that at quasi-static strain rates, while distinct localized fracture surface morphology was observed for specimens tested at different strain rates. The transverse compressive yield stress and strength at a strain rate of 325 s−1 increased by 94% and 96%, respectively, when compared to those at quasi-static strain rates. The initial fracture plane orientation for the transverse compression tests was captured with high-speed cameras and found to increase with increasing strain rate. The study provides an important data set for the strain rate-dependent response of a UD-NCF composite material, while the qualitative fracture surface observations provide a deeper understanding of the failure characteristics.

Thermally induced damage initiation and growth in carbon-carbon composites

1997 ◽  
Author(s):  
Clinton Chapman ◽  
John Whitcomb ◽  
Clinton Chapman ◽  
John Whitcomb
Keyword(s):  
Carbon Composites ◽  
Thermally Induced ◽  
Damage Initiation

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.

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