on plastic void growth in strong ductile materials
... according to Eq. (4.14). The results are for Y /E = 1/500, and for three values of the hardening modulus k/E = 1/100, 1/50, and 1/25 (from lower to upper curve). ...
... according to Eq. (4.14). The results are for Y /E = 1/500, and for three values of the hardening modulus k/E = 1/100, 1/50, and 1/25 (from lower to upper curve). ...
Chapter 3 Fracture
... microscopic flaws. The applied stress is amplified at the tips of micro-cracks, voids, notches, surface scratches, corners, etc. that are called stress raisers. The magnitude of this amplification depends on micro-crack orientations, geometry and dimensions. ...
... microscopic flaws. The applied stress is amplified at the tips of micro-cracks, voids, notches, surface scratches, corners, etc. that are called stress raisers. The magnitude of this amplification depends on micro-crack orientations, geometry and dimensions. ...
Liu.pdf
... The low cycle fatigue life (LCFL) of the aeronautical engine turbine disc structure is related to the stress–strain level of the disc applied by cyclic load and the life characteristic of the material. The randomness of the basic variables, such as applied load, working temperature, geometrical dime ...
... The low cycle fatigue life (LCFL) of the aeronautical engine turbine disc structure is related to the stress–strain level of the disc applied by cyclic load and the life characteristic of the material. The randomness of the basic variables, such as applied load, working temperature, geometrical dime ...
Theories of Failure
... failure criterion for brittle materials in static loading if compressive and tensile strengths were equal (even material). The maximum-normal stress theory envelope for an uneven material as the asymmetric square of half-dimensions Sut, - Suc is also shown. This failure envelope is only valid in the ...
... failure criterion for brittle materials in static loading if compressive and tensile strengths were equal (even material). The maximum-normal stress theory envelope for an uneven material as the asymmetric square of half-dimensions Sut, - Suc is also shown. This failure envelope is only valid in the ...
Laboratory experiments, high angular
... of differential stresses applied during deformation. Stresses averaged over each map are in reasonable agreement with the outcome of stress-dip tests. Third, we implement an elasto-visco-plastic spectral micromechanical model to predict the full stress field in a deforming olivine aggregate. An EBSD ...
... of differential stresses applied during deformation. Stresses averaged over each map are in reasonable agreement with the outcome of stress-dip tests. Third, we implement an elasto-visco-plastic spectral micromechanical model to predict the full stress field in a deforming olivine aggregate. An EBSD ...
Stress Concentration Factors of Matrix in a Composite Subjected to
... In order to predict failure behavior and ultimate strength of a fibrous composite only based on its original constituent material properties, three challenging problems must be resolved with high success. First, the internal stresses in the constituent fiber and matrix materials must be accurately e ...
... In order to predict failure behavior and ultimate strength of a fibrous composite only based on its original constituent material properties, three challenging problems must be resolved with high success. First, the internal stresses in the constituent fiber and matrix materials must be accurately e ...
Chapter 5 - Stress in Fluids
... we can invoke the known properties of symmetric tensors. In particular, there are three principal directions and referred to coordinates parallel to these, the shear stresses vanish. The direct stresses with these coordinates are called the principal stresses and the axes the principal axes of stres ...
... we can invoke the known properties of symmetric tensors. In particular, there are three principal directions and referred to coordinates parallel to these, the shear stresses vanish. The direct stresses with these coordinates are called the principal stresses and the axes the principal axes of stres ...
0739.PDF
... show a typical "ramping" above the Hugoniot Elastic Limit (HEL). Under the assumption that the HEL signifies the beginning of failure of the material, this "ramping" has been described by viscoplasticity or by moduli degradation. However, there is ample experimental evidence to rule out plastic flow ...
... show a typical "ramping" above the Hugoniot Elastic Limit (HEL). Under the assumption that the HEL signifies the beginning of failure of the material, this "ramping" has been described by viscoplasticity or by moduli degradation. However, there is ample experimental evidence to rule out plastic flow ...
A Novel 3D Finite Element Simulation Model for
... was analyzed experimentally by x-ray diffraction measurements at a shot peened test specimen featuring different thicknesses and numerically by 3D FE simulations using three different approaches for constraining the model boundaries. It was found that with the classic approach of symmetric boundarie ...
... was analyzed experimentally by x-ray diffraction measurements at a shot peened test specimen featuring different thicknesses and numerically by 3D FE simulations using three different approaches for constraining the model boundaries. It was found that with the classic approach of symmetric boundarie ...
10 - PSU MNE
... Once specimen necking starts, the material fails, because the cross-sectional area in the necked region becomes progressively smaller, and thus no additional load is needed to cause further deformation. The stress at which necking occurs is called the ultimate tensile strength of the material or U ...
... Once specimen necking starts, the material fails, because the cross-sectional area in the necked region becomes progressively smaller, and thus no additional load is needed to cause further deformation. The stress at which necking occurs is called the ultimate tensile strength of the material or U ...
Relationship between Yield stress and yield Strength on Various
... Aiyedun, P.O., Oseghale, L.E., and Alamu, O.J. (2009), “Simulation of Load Bearing Rod Rolling ofCarbon-Manganese Steel Using the “Phantom Roll” Method,” Pacific Journal of Science and Technology, Vol.10, pp 4-14. Aiyedun, P.O. (1999), “Yield Stress Variation across thickness for Steel (HC SS316) Sp ...
... Aiyedun, P.O., Oseghale, L.E., and Alamu, O.J. (2009), “Simulation of Load Bearing Rod Rolling ofCarbon-Manganese Steel Using the “Phantom Roll” Method,” Pacific Journal of Science and Technology, Vol.10, pp 4-14. Aiyedun, P.O. (1999), “Yield Stress Variation across thickness for Steel (HC SS316) Sp ...
Spring Forces and Simple Harmonic Motion
... If the only force doing work on an object is the spring force (conservative), its mechanical energy is conserved. If frictional forces also do work, the object’s mechanical energy decreases, and the SHM is called damped. If the frictional force is just large enough to prevent oscillation as the obje ...
... If the only force doing work on an object is the spring force (conservative), its mechanical energy is conserved. If frictional forces also do work, the object’s mechanical energy decreases, and the SHM is called damped. If the frictional force is just large enough to prevent oscillation as the obje ...
Large-strain time-temperature equivalence in high density
... 10.2◦ C and 10.6◦ C reduction in temperature, respectively. It is also important to note that their results also revealed substantial adiabatic heating and softening of the materials at strain-rates above 0.1 s−1 . This work also tracked the temperature–strain-rate equivalence of the flow stress at ...
... 10.2◦ C and 10.6◦ C reduction in temperature, respectively. It is also important to note that their results also revealed substantial adiabatic heating and softening of the materials at strain-rates above 0.1 s−1 . This work also tracked the temperature–strain-rate equivalence of the flow stress at ...
Modeling of articular cartilage replacement materials
... The present investigation focuses on three goals: The first one is the development of a strain rate-dependent tensor formulation for viscoelasticity and diffusion, which is necessary for the VED model in a phenomenological manner. The deformation-dependent diffusion is described by two different evoluti ...
... The present investigation focuses on three goals: The first one is the development of a strain rate-dependent tensor formulation for viscoelasticity and diffusion, which is necessary for the VED model in a phenomenological manner. The deformation-dependent diffusion is described by two different evoluti ...
Slide 1
... Consider the relation between the shear stress yx and the shear deformation rate du/dy. Newtonian fluids are the fluids in which shear stress is linearly proportional to shear deformation rate. ...
... Consider the relation between the shear stress yx and the shear deformation rate du/dy. Newtonian fluids are the fluids in which shear stress is linearly proportional to shear deformation rate. ...
Chapter 12
... The elastic limit is the maximum stress that can be applied to the substance before it becomes permanently deformed When the stress exceeds the elastic limit, the substance will be permanently deformed ...
... The elastic limit is the maximum stress that can be applied to the substance before it becomes permanently deformed When the stress exceeds the elastic limit, the substance will be permanently deformed ...
Chapter 12
... The elastic limit is the maximum stress that can be applied to the substance before it becomes permanently deformed When the stress exceeds the elastic limit, the substance will be permanently defined ...
... The elastic limit is the maximum stress that can be applied to the substance before it becomes permanently deformed When the stress exceeds the elastic limit, the substance will be permanently defined ...
Chapter 12
... The elastic limit is the maximum stress that can be applied to the substance before it becomes permanently deformed When the stress exceeds the elastic limit, the substance will be permanently defined ...
... The elastic limit is the maximum stress that can be applied to the substance before it becomes permanently deformed When the stress exceeds the elastic limit, the substance will be permanently defined ...
An energy-based approach for estimates of the stress-strain
... in the last decades. This happens in spite of the existence of a small volume of material in front of the crack (plastic zone) where the stresses are well above the yield point. The analysis of stress in notches, needed almost exclusively for fatigue design purposes, is performed with the help of th ...
... in the last decades. This happens in spite of the existence of a small volume of material in front of the crack (plastic zone) where the stresses are well above the yield point. The analysis of stress in notches, needed almost exclusively for fatigue design purposes, is performed with the help of th ...
LEC. 7: Stress I – Introduction to Dynamic Analysis
... A force is that which changes the state of rest/motion of a body. Remember Newton’s First Law of Motion: an object at rest will remain at rest until acted on by an external force. Newton’s Second Law of Motion: The acceleration of an object is proportional to the force acted on it, and, inversely pr ...
... A force is that which changes the state of rest/motion of a body. Remember Newton’s First Law of Motion: an object at rest will remain at rest until acted on by an external force. Newton’s Second Law of Motion: The acceleration of an object is proportional to the force acted on it, and, inversely pr ...
CHE 333 Class 19
... growth in a material. Simple energy balance used – energy applied is the stress and it is used up by creating fresh surface. Works well for brittle materials where no plastic deformation. For ductile materials energy absorbed is complicated by plastic deformation. Fracture mechanics relates the size ...
... growth in a material. Simple energy balance used – energy applied is the stress and it is used up by creating fresh surface. Works well for brittle materials where no plastic deformation. For ductile materials energy absorbed is complicated by plastic deformation. Fracture mechanics relates the size ...
CTE3-Script.pdf
... Continuum Mechanics is the branch of mechanics used to investigate the deformation and flow of materials subjected to loads. Is a generalization of the classical Newtonian mechanics to macroscopic bodies. These bodies are considered formed by infinite collections of material points. As in classical ...
... Continuum Mechanics is the branch of mechanics used to investigate the deformation and flow of materials subjected to loads. Is a generalization of the classical Newtonian mechanics to macroscopic bodies. These bodies are considered formed by infinite collections of material points. As in classical ...
Lecture 7 Mechanical Properties of Rocks
... on any given plane besides the principal stresses. In general, this is a three dimensional problem and can be done using mathematical tensors and vectors. In a special case where we can assume that the intermediate and minimum stresses are equal (for example below the ground surface), we can work ...
... on any given plane besides the principal stresses. In general, this is a three dimensional problem and can be done using mathematical tensors and vectors. In a special case where we can assume that the intermediate and minimum stresses are equal (for example below the ground surface), we can work ...
Failure Modes
... not recover its original dimension & it is said to have undergone plastic deformation or plastic flow • The upper is yield point & denoted by YU, the highest stress before sudden extension occurs. • The lower YP (YL) is the lowest stress producing the large elongation • Two yield points are noticed ...
... not recover its original dimension & it is said to have undergone plastic deformation or plastic flow • The upper is yield point & denoted by YU, the highest stress before sudden extension occurs. • The lower YP (YL) is the lowest stress producing the large elongation • Two yield points are noticed ...
Viscoplasticity
Viscoplasticity is a theory in continuum mechanics that describes the rate-dependent inelastic behavior of solids. Rate-dependence in this context means that the deformation of the material depends on the rate at which loads are applied. The inelastic behavior that is the subject of viscoplasticity is plastic deformation which means that the material undergoes unrecoverable deformations when a load level is reached. Rate-dependent plasticity is important for transient plasticity calculations. The main difference between rate-independent plastic and viscoplastic material models is that the latter exhibit not only permanent deformations after the application of loads but continue to undergo a creep flow as a function of time under the influence of the applied load.The elastic response of viscoplastic materials can be represented in one-dimension by Hookean spring elements. Rate-dependence can be represented by nonlinear dashpot elements in a manner similar to viscoelasticity. Plasticity can be accounted for by adding sliding frictional elements as shown in Figure 1. In the figure E is the modulus of elasticity, λ is the viscosity parameter and N is a power-law type parameter that represents non-linear dashpot [σ(dε/dt)= σ = λ(dε/dt)(1/N)]. The sliding element can have a yield stress (σy) that is strain rate dependent, or even constant, as shown in Figure 1c.Viscoplasticity is usually modeled in three-dimensions using overstress models of the Perzyna or Duvaut-Lions types. In these models, the stress is allowed to increase beyond the rate-independent yield surface upon application of a load and then allowed to relax back to the yield surface over time. The yield surface is usually assumed not to be rate-dependent in such models. An alternative approach is to add a strain rate dependence to the yield stress and use the techniques of rate independent plasticity to calculate the response of a materialFor metals and alloys, viscoplasticity is the macroscopic behavior caused by a mechanism linked to the movement of dislocations in grains, with superposed effects of inter-crystalline gliding. The mechanism usually becomes dominant at temperatures greater than approximately one third of the absolute melting temperature. However, certain alloys exhibit viscoplasticity at room temperature (300K). For polymers, wood, and bitumen, the theory of viscoplasticity is required to describe behavior beyond the limit of elasticity or viscoelasticity. In general, viscoplasticity theories are useful in areas such as the calculation of permanent deformations, the prediction of the plastic collapse of structures, the investigation of stability, crash simulations, systems exposed to high temperatures such as turbines in engines, e.g. a power plant, dynamic problems and systems exposed to high strain rates.↑ ↑ ↑ ↑