structural implications of ultra-high performance fibre
... and non-negligible tensile strength and ductility, provided by multi-microcracking. This allows significant tensile forces to be sustained by elements in bending even without the use of ordinary reinforcement. Thanks also to the material’s resistance to environmental degradation, very thin structura ...
... and non-negligible tensile strength and ductility, provided by multi-microcracking. This allows significant tensile forces to be sustained by elements in bending even without the use of ordinary reinforcement. Thanks also to the material’s resistance to environmental degradation, very thin structura ...
Chapter 10 Elasticity & Oscillations
... structure's natural mode of vibration to produce rapid periodic motion. Flutter can occur in any object within a strong fluid flow, under the conditions that a positive feedback occurs between the structure's natural vibration and the aerodynamic forces. That is, that the vibrational movement of the ...
... structure's natural mode of vibration to produce rapid periodic motion. Flutter can occur in any object within a strong fluid flow, under the conditions that a positive feedback occurs between the structure's natural vibration and the aerodynamic forces. That is, that the vibrational movement of the ...
Chapter 10 Elasticity & Oscillations
... structure's natural mode of vibration to produce rapid periodic motion. Flutter can occur in any object within a strong fluid flow, under the conditions that a positive feedback occurs between the structure's natural vibration and the aerodynamic forces. That is, that the vibrational movement of the ...
... structure's natural mode of vibration to produce rapid periodic motion. Flutter can occur in any object within a strong fluid flow, under the conditions that a positive feedback occurs between the structure's natural vibration and the aerodynamic forces. That is, that the vibrational movement of the ...
Ability of a Bacterial Chromosome Segment to Invert Is
... in E. coli have led to slightly different conclusions and will be discussed later. In the experiments presented here, we wish to test the effect of changes in the orientation and chromosomal position of a particular arc of chromosome on the permissivity of inverting other segments of the chromosome. ...
... in E. coli have led to slightly different conclusions and will be discussed later. In the experiments presented here, we wish to test the effect of changes in the orientation and chromosomal position of a particular arc of chromosome on the permissivity of inverting other segments of the chromosome. ...
Ab initio modelling of mechanical and elastic properties of solids
... metallurgy and mechanical engineering. Following the spirit of materials science in combination with fundamental research, the present work tries to link the interactions between atoms modelled by concepts of quantum physics to the macroscopic mechanical behaviour of materials. The most elementary - ...
... metallurgy and mechanical engineering. Following the spirit of materials science in combination with fundamental research, the present work tries to link the interactions between atoms modelled by concepts of quantum physics to the macroscopic mechanical behaviour of materials. The most elementary - ...
combined effects of interstitial and laplace pressure in hot isostatic
... The present work is focused on modeling the evolution of material properties during sintering of axisymmetric samples. It is a natural extension of [Olevsky and Molinari 2006], dealing with an analysis of the kinetics and stability of porous axially symmetric bodies undergoing sintering under differ ...
... The present work is focused on modeling the evolution of material properties during sintering of axisymmetric samples. It is a natural extension of [Olevsky and Molinari 2006], dealing with an analysis of the kinetics and stability of porous axially symmetric bodies undergoing sintering under differ ...
Piezo-Fundamentals.pdf
... This chapter is concerned with piezoelectric materials and their properties. We begin the chapter with a brief overview of some historical milestones, such as the discovery of the piezoelectric effect, the invention of piezoelectric ceramic materials, and commercial and military utilization of the te ...
... This chapter is concerned with piezoelectric materials and their properties. We begin the chapter with a brief overview of some historical milestones, such as the discovery of the piezoelectric effect, the invention of piezoelectric ceramic materials, and commercial and military utilization of the te ...
FATIGUE LIFE OF GRAPHITE/EPOXY LAMINATES SUBJECTED TO
... trend is observed from the data in Table III: when |mmin| increases, `t also increases, whereas _ t decreases progressively. Since, from eq. (7), an increase in both the constants results in a poorer response in fatigue, the actual trend of the fatigue life in the case concerned cannot be easily gue ...
... trend is observed from the data in Table III: when |mmin| increases, `t also increases, whereas _ t decreases progressively. Since, from eq. (7), an increase in both the constants results in a poorer response in fatigue, the actual trend of the fatigue life in the case concerned cannot be easily gue ...
Determination of Actual Friction Factors in Metal Forming
... to characterize friction between two surfaces is to define a friction factor at the work piece-die interface. To evaluate the behavior of lubricants in metal forming processes, it is common to quantify the friction factor using different indirect techniques, such as the open-die backward extrusion t ...
... to characterize friction between two surfaces is to define a friction factor at the work piece-die interface. To evaluate the behavior of lubricants in metal forming processes, it is common to quantify the friction factor using different indirect techniques, such as the open-die backward extrusion t ...
Effects of the Laplace pressure and of gas pressure on isostatic
... In the last decades, powder technology has become one of the most important technological processes for the production of metallic and ceramics components; free sintering, hot isostatic pressing and hot forging are different ways to realize a key-phase in which the primary mechanical properties of th ...
... In the last decades, powder technology has become one of the most important technological processes for the production of metallic and ceramics components; free sintering, hot isostatic pressing and hot forging are different ways to realize a key-phase in which the primary mechanical properties of th ...
Elastic and Inelastic Shock Compression of Diamond and Other
... deformation above the elastic limit. The idealized model of total strength loss beyond the elastic limit is termed elastic-isotropic, in the sense that compression to the elastic limit is one of elastic uniaxial strain, while compression beyond the limit produces states of isotropic stress and strai ...
... deformation above the elastic limit. The idealized model of total strength loss beyond the elastic limit is termed elastic-isotropic, in the sense that compression to the elastic limit is one of elastic uniaxial strain, while compression beyond the limit produces states of isotropic stress and strai ...
Failure modes of composite sandwich beams
... of the beam to prevent premature core failures. Also, under three-point bending, the faces directly under concentrated loads were reinforced with additional layers of carbon/epoxy to suppress and prevent indentation failure. Only in the case when the indentation failure mode was studied, there was n ...
... of the beam to prevent premature core failures. Also, under three-point bending, the faces directly under concentrated loads were reinforced with additional layers of carbon/epoxy to suppress and prevent indentation failure. Only in the case when the indentation failure mode was studied, there was n ...
Bounding the plastic strength of polycrystalline solids by linear
... resulting surface (3.8) bounds from the outside the strength domain of all polycrystals belonging to that particular subclass—see Nebozhyn et al. (2001). In turn, the computation of the functions v (r) in v requires the solution of the optimization problem (3.3). Since the P (r) are closed convex se ...
... resulting surface (3.8) bounds from the outside the strength domain of all polycrystals belonging to that particular subclass—see Nebozhyn et al. (2001). In turn, the computation of the functions v (r) in v requires the solution of the optimization problem (3.3). Since the P (r) are closed convex se ...
An Investigation of Anterior Cruciate Ligament Injuries and Analysis
... referenced in this study. In this analysis of the BPTB graft, two tests will be performed with certain boundary conditions. During ACL reconstruction surgery, femoral and tibial tunnels are drilled through the femur and tibia, then the BPTB graft is screwed into the femur, tension is applied, and la ...
... referenced in this study. In this analysis of the BPTB graft, two tests will be performed with certain boundary conditions. During ACL reconstruction surgery, femoral and tibial tunnels are drilled through the femur and tibia, then the BPTB graft is screwed into the femur, tension is applied, and la ...
The impact behaviour of silk cocoons
... modes caused by the local indentation described above. In previous work we have shown that models based upon open-cell foam structures describe the mechanical properties of silk cocoons (Chen et al., 2010b). Here we therefore use the finite element software ABAQUS/CAE 6.8-4 (Dassault Systèmes, Véliz ...
... modes caused by the local indentation described above. In previous work we have shown that models based upon open-cell foam structures describe the mechanical properties of silk cocoons (Chen et al., 2010b). Here we therefore use the finite element software ABAQUS/CAE 6.8-4 (Dassault Systèmes, Véliz ...
Structure and Mechanical Properties of Fe-Mn Alloys
... Materials for automobile applications need both the high strength and good ductility. A combination of these beneficial mechanical properties requires sustained high strain hardening rate throughout the course of plasticity. Fe-Mn alloys are a good example of demonstrating such exceptional mechanical ...
... Materials for automobile applications need both the high strength and good ductility. A combination of these beneficial mechanical properties requires sustained high strain hardening rate throughout the course of plasticity. Fe-Mn alloys are a good example of demonstrating such exceptional mechanical ...
An evaluation of switching criteria for ferroelectrics under stress and
... ferroelectric sensors operate within the linear regime with subsequent signal amplification: linearity is more important than signal power. In other applications such as ferroelectric actuators, nonlinear behaviour is a consequence of operating at high power. It is useful to introduce the concept of ...
... ferroelectric sensors operate within the linear regime with subsequent signal amplification: linearity is more important than signal power. In other applications such as ferroelectric actuators, nonlinear behaviour is a consequence of operating at high power. It is useful to introduce the concept of ...
Mechanical Properties of Pedal Mucus and Their Consequences for
... dry, at small deformations. Denny (1983) has reviewed the existing knowledge of the chemistry and mechanical properties of gastropod pedal mucus. This information is not extensive, but the properties of A. columbianus pedal mucus have been examined under each of these conditions and thus provide a m ...
... dry, at small deformations. Denny (1983) has reviewed the existing knowledge of the chemistry and mechanical properties of gastropod pedal mucus. This information is not extensive, but the properties of A. columbianus pedal mucus have been examined under each of these conditions and thus provide a m ...
me337_s17
... growth, remodeling and morphogenesis morphogenesis is the generation of animal form. usually, the term refers to embryonic development, but wound healing and organ regeneration are also morphogenetic events. morphogenesis contains a complex series of stages, each of which depends on the previous st ...
... growth, remodeling and morphogenesis morphogenesis is the generation of animal form. usually, the term refers to embryonic development, but wound healing and organ regeneration are also morphogenetic events. morphogenesis contains a complex series of stages, each of which depends on the previous st ...
A review on shape memory alloys with applications to morphing
... et al (2008) showed that it is possible to create NiTi materials with enlarged transformation intervals, either in stress or in temperature. They investigated a novel concept of partially annealing cold-worked near-equi-atomic NiTi alloys within a range of temperatures to create structurally graded ...
... et al (2008) showed that it is possible to create NiTi materials with enlarged transformation intervals, either in stress or in temperature. They investigated a novel concept of partially annealing cold-worked near-equi-atomic NiTi alloys within a range of temperatures to create structurally graded ...
The fracture toughness of a cordierite square lattice
... For the choice a=H ¼ 0:5, this strength criterion reduces to rcr =ru ¼ 1=4 and this prediction has been added to Fig. 4. A transition in behaviour is predicted from notchinsensitive behaviour to the LEFM limit with increasing crack length. We proceed to confirm or refute the above predictions for the ...
... For the choice a=H ¼ 0:5, this strength criterion reduces to rcr =ru ¼ 1=4 and this prediction has been added to Fig. 4. A transition in behaviour is predicted from notchinsensitive behaviour to the LEFM limit with increasing crack length. We proceed to confirm or refute the above predictions for the ...
high strain rate behaviour of woven composite
... The thesis centres on the dynamic behaviour of woven composite materials. The increase in the use of these materials in the aerospace industry demands a reliable constitutive damage model to predict their response under high strain rate loading. The current available models do not include rate effec ...
... The thesis centres on the dynamic behaviour of woven composite materials. The increase in the use of these materials in the aerospace industry demands a reliable constitutive damage model to predict their response under high strain rate loading. The current available models do not include rate effec ...
Quasistatic Deformation and Failure Modes of Composite Square Honeycombs
... height to width and the number of cells in the specimen. The measurements indicate that the response is relatively insensitive to the ratio of the cell height to cell width and number of cells in the specimen but is strongly dependent on the laminate type and fibre orientation. For example, the comp ...
... height to width and the number of cells in the specimen. The measurements indicate that the response is relatively insensitive to the ratio of the cell height to cell width and number of cells in the specimen but is strongly dependent on the laminate type and fibre orientation. For example, the comp ...
On small deformation interfacial debonding in composite materials
... using nonlinear cohesive models, which assume a phenomenological relation between the traction and separation at the interface. For instance, Xu and Needleman24 investigated void nucleation along the interface in conjunction with an exponential cohesive relation. Using a bilinear cohesive relation, ...
... using nonlinear cohesive models, which assume a phenomenological relation between the traction and separation at the interface. For instance, Xu and Needleman24 investigated void nucleation along the interface in conjunction with an exponential cohesive relation. Using a bilinear cohesive relation, ...
Molecular - Acclab h55.it.helsinki.fi
... Modelling and Simulation in Materials Science and Engineering Modelling Simul. Mater. Sci. Eng. 23 (2015) 025009 (17pp) ...
... Modelling and Simulation in Materials Science and Engineering Modelling Simul. Mater. Sci. Eng. 23 (2015) 025009 (17pp) ...
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.↑ ↑ ↑ ↑