Dependence of deformation indices on initial yield strength and hardening intensity of wire material in the passage of drawing route

The model of hardening is considered, which provides for dependence of the current yield strength σт on the product of the initial yield strength σт0 and drawing coeffi cient μ to the degree of hardening coeffi cient k (σт = σт0μk). Difference of axial stress increase from action of anti-tension in absence and action of hardening depending on hardening coeffi cient is determined. Dependencies of drawing stress, safety factor I.L. Perlin and stress state index V.L. Kolmogorov on hardening coeffi cient at different values of initial yield strength are built. Limit hardening factor k is defi ned, at which safety factor is equal to 1. Dependencies of deformation indices on initial yield strength of σт0 at different deformation parameters are constructed.

Effects of Sous-vide Cooking on the Initial Yield, Peak Force, and Elastic Modulus of Cooked Beef Semitendinosus

The objective of this study was to compare the traditional cooking method with sous-vide cooking at various cooking temperatures and times on the initial yield, peak force, and elastic modulus of semitendinosus (ST) beef. This study also examined the colour properties, cooking loss, and water retention of ST beef. Sous-vide samples were cooked inside vacuumized pouches at temperatures 60, 70, and 80 ℃ for 3 and 6 h. Meanwhile, the traditional cooking method was treated at 90℃ for 30 min. Reduced the initial yield, peak force, and elastic modulus of ST beef could be attained in 6 h at 60 ℃. Higher temperature and prolonged cooking time seem to cause meat to be tougher, likely due to the longitudinal myofibrils shrank. In terms of water retention and cooking loss, sous-vide cooked at 60 °C (regardless of cooking time) significantly exhibited better water retention and lower cook loss. This mild cooking temperature also best preserved the colour properties of lightness (L*) and redness (a*) than the other treatments.

Fuzzy Plastic Constitutive Model and Its Application to Subgrade

The subgrade of a road is subjected to cyclic loading and unloading under the action of traffic loads. To study this mechanical response, the plastic membership function was introduced into the modified Cambridge model, and thus, the fuzzy plastic Cambridge constitutive model was obtained. With the continuous evolution of the plastic membership function from 0 to 1, the fuzzy plastic Cambridge constitutive model continuously transitions the plastic properties inside and outside the initial yield surface. The evolution of the plastic membership function can replace the complex hardening law. The reliability of the model was verified using triaxial tests and simple cyclic loading and unloading tests. Using the finite element method, the mechanical response of the subgrade under cyclic loading was calculated. The fuzzy plastic Cambridge model can explain the insignificant yield characteristics of geotechnical media. In the fuzzy plasticity theory, the stress inside and outside the initial yield surface can produce plasticity. Absolute plasticity was not observed; only different degrees of plasticity existed.

Overview of an Experimental Program for Development of Yield Surfaces Tracing Method

This paper develops an experimental technique to evaluate the initial yield surfaces of metallic materials, as well as to study their evolution during plastic flow. The experimental tracing of yield surfaces is necessary for deriving and calibrating more robust phenomenological models of directional distortional hardening. Such models can be used to characterize the behavior of structures experiencing complicated and demanding loading modes, such as multiaxial ratcheting. The experimental technique developed in this work uses thin-walled tubular specimens, along with a servo-hydraulic machine, under various modes of tension/compression and torque. Identification of the onset of plastic flow is based on a small proof equivalent plastic strain evaluated from the outputs of a contact biaxial extensometer firmly attached to a specimen surface. This allows for evaluation of both the initial yield surface, as well as theevolved yield surface after a plastic prestrain. Throughout a test, continuous and fully automatized evaluation of elastic moduli and proof plastic strain is assured through algorithms written in C# language. The current technique is shown to provide promising results to effectively capture the yield surfaces of conventional metallic materials.

Do investors value frequent issuers in securitization?

We assess the value of frequent issuers to investors in securitization markets by examining the initial yield spread of 6132 European mortgage-backed securities (MBS), covering a 20-year period between 1999 and 2018. We find that frequent issuers have certification value, and it increases as the credit cycle approaches its peak, as lending standards loosen, and information asymmetries in securitization markets increase. Investors value frequent issuers more favourably on riskier, difficult to evaluate MBS. We find that after the great financial crisis (GFC), investors began to attribute more value to frequent issuers, regardless of MBS credit quality. We also find that in the pre-crisis period, investors required higher yields to compensate for perceived rating shopping, which is not observed after the GFC. Finally, we show that investors expect higher yields on deals closed by subsidiaries of foreign banks.

Some classical problems in rate-independent plasticity

This chapter presents analytical solutions to some classical problems in rate-independent plasticity. Solutions are presented for the elastic-plastic torsion of a round bar, including spring back; for the elastic-plastic response of a thick-walled spherical pressure vessel, including initial yield, partial yield, full yield, and unloading; for the incompressible elastic-plastic response of a plane-strain thick-walled cylindrical pressure vessel, including initial yield, partial yield, and full yield.