scholarly journals Mapping of Texture and Phase Fractions in Heterogeneous Stress States during Multiaxial Loading of Biomedical Superelastic NiTi

2020 ◽  
pp. 2005092
Author(s):  
Douglas E. Nicholson ◽  
Santo A. Padula ◽  
Othmane Benafan ◽  
Jeffrey R. Bunn ◽  
E. Andrew Payzant ◽  
...  
Keyword(s):  
Multiaxial Loading ◽  
Stress States

Axial-Shear Failure Behavior of Human Femoral Trabecular Bone

1999 ◽  
Author(s):  
Yves P. Arramon ◽  
Oscar C. Yeh ◽  
Elise F. Morgan ◽  
Tony M. Keaveny
Keyword(s):  
Mechanical Behavior ◽  
Trabecular Bone ◽  
Failure Criterion ◽  
Shear Failure ◽  
Computer Models ◽  
Failure Behavior ◽  
Multiaxial Loading ◽  
Bone Implant ◽  
Computer Aided ◽  
Stress States

Abstract An understanding of the failure of trabecular bone subjected to multiaxial loading has relevance in the mechanics of trauma and bone implant interfaces. The development of computer aided tomography-based computer models allow predictions of the mechanical behavior of whole bones when subjected to stress states too complex to be described analytically (Ford et al., 1996; Keyak et al., 1998; Oden et al., 1998). However, these models cannot confidently predict the failure of the trabecular bone without an experimentally validated multiaxial failure criterion.

Comparison of Substructures Between Uniaxial and Biaxial Deformation in 1100-0 Aluminum

1981 ◽  
Vol 39 ◽  
pp. 52-53
Author(s):  
D. L. Rohr ◽  
S. S. Hecker
Keyword(s):  
Plastic Strain ◽  
Cell Walls ◽  
Room Temperature ◽  
Mechanical Response ◽  
Biaxial Tension ◽  
Initial Deformation ◽  
Uniaxial Deformation ◽  
Biaxial Deformation ◽  
Stress States ◽  
Comprehensive Study

As part of a comprehensive study of microstructural and mechanical response of metals to uniaxial and biaxial deformations, the development of substructure in 1100 A1 has been studied over a range of plastic strain for two stress states.Specimens of 1100 aluminum annealed at 350 C were tested in uniaxial (UT) and balanced biaxial tension (BBT) at room temperature to different strain levels. The biaxial specimens were produced by the in-plane punch stretching technique. Areas of known strain levels were prepared for TEM by lapping followed by jet electropolishing. All specimens were examined in a JEOL 200B run at 150 and 200 kV within 24 to 36 hours after testing.The development of the substructure with deformation is shown in Fig. 1 for both stress states. Initial deformation produces dislocation tangles, which form cell walls by 10% uniaxial deformation, and start to recover to form subgrains by 25%. The results of several hundred measurements of cell/subgrain sizes by a linear intercept technique are presented in Table I.

Short Stress State Questionnaire

2015 ◽  
Vol 31 (1) ◽  
pp. 20-30 ◽  
Author(s):  
William S. Helton ◽  
Katharina Näswall
Keyword(s):  
Stress State ◽  
Factor Structure ◽  
Human Performance ◽  
Self Report ◽  
Confirmatory Factor ◽  
Stress States ◽  
Related Stress ◽  
Using Data ◽  
Task Conditions ◽  
Multiple Samples

Conscious appraisals of stress, or stress states, are an important aspect of human performance. This article presents evidence supporting the validity and measurement characteristics of a short multidimensional self-report measure of stress state, the Short Stress State Questionnaire (SSSQ; Helton, 2004 ). The SSSQ measures task engagement, distress, and worry. A confirmatory factor analysis of the SSSQ using data pooled from multiple samples suggests the SSSQ does have a three factor structure and post-task changes are not due to changes in factor structure, but to mean level changes (state changes). In addition, the SSSQ demonstrates sensitivity to task stressors in line with hypotheses. Different task conditions elicited unique patterns of stress state on the three factors of the SSSQ in line with prior predictions. The 24-item SSSQ is a valid measure of stress state which may be useful to researchers interested in conscious appraisals of task-related stress.

Masonry: the brittle or plastic material?

2019 ◽  
pp. 22-28
Keyword(s):  
Plastic Material ◽  
Experimental Studies ◽  
Point Of View ◽  
Plastic Properties ◽  
Plastic Deformations ◽  
Base Materials ◽  
Stress States ◽  
Creep Deformations ◽  
Structural Point

The results of experimental studies of masonry on the action of dynamic and static (short-term and long-term) loads are presented. The possibility of plastic deformations in the masonry is analyzed for different types of force effects. The falsity of the proposed approach to the estimation of the coefficient of plasticity of masonry, taking into account the ratio of elastic and total deformations of the masonry is noted. The study of the works of Soviet scientists revealed that the masonry under the action of seismic loads refers to brittle materials in the complete absence of plastic properties in it in the process of instantaneous application of forces. For the cases of uniaxial and plane stress states of the masonry, data on the coefficient of plasticity obtained from the experiment are presented. On the basis of experimental studies the influence of the strength of the so-called base materials (brick, mortar) on the bearing capacity of the masonry, regardless of the nature of the application of forces and the type of its stress state, is noted. The analysis of works of prof. S. V. Polyakov makes it possible to draw a conclusion that at the long application of the load, characteristic for the masonry are not plastic deformations, but creep deformations. It is shown that the proposals of some authors on the need to reduce the level of adhesion of the mortar to the brick for the masonry erected in earthquake-prone regions in order to improve its plastic properties are erroneous both from the structural point of view and from the point of view of ensuring the seismic resistance of structures. It is noted that the proposal to assess the plasticity of the masonry of ceramic brick walls and large-format ceramic stone with a voidness of more than 20% is incorrect, and does not meet the work of the masonry of hollow material. On the basis of the analysis of a large number of research works it is concluded about the fragile work of masonry.

High Fidelity Response and Failure Evaluation of Tapered Composite Components under Multiaxial Loading

2021 ◽  
Author(s):  
Jian Xiao ◽  
Phillip Liu ◽  
D.C. Pham ◽  
Jim Lua ◽  
Shenal Perera ◽  
...  
Keyword(s):  
High Fidelity ◽  
Multiaxial Loading ◽  
Failure Evaluation

Deformation and damage behavior of lightweight steels at high rate multiaxial loading

2016 ◽  
Vol 58 (3) ◽  
pp. 173-181 ◽  
Author(s):  
Silke Klitschke ◽  
Wolfgang Böhme
Keyword(s):  
High Rate ◽  
Multiaxial Loading ◽  
Damage Behavior

Variation of Stresses Ahead of The Internal Cracks in ReNI5 Powders During Hydrogen Charging and Discharging Cycles

1997 ◽  
Vol 496 ◽  
Author(s):  
S. B. Biner
Keyword(s):  
Modulus Of Elasticity ◽  
Spherical Particles ◽  
Tensile Stresses ◽  
Hydrogen Charging ◽  
Coupled Diffusion ◽  
Stress States

ABSTRACTIn this study, the evolution of the stress-states ahead of the penny shaped internal cracks in both spherical and disk shaped ReNi5 particles during hydrogen charging and discharging cycles were investigated using coupled diffusion/deformation FEM analyses. The results indicate that large tensile stresses, on the order of 20–50% of the modulus of elasticity, develop in the particles. The disk shaped particles, in addition to having faster charging/discharging cycles, may offer better resistance to fracture than the spherical particles.

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