In this paper a simple tool for seismic design of steel structures for a selected ductility level is presented. For this purpose, a consistent set of earthquakes is selected and sorted based on the maximum acceleration of ground surface. The selected records are applied as the base motion to a single-degree-of-freedom system with strain hardening and the maximum response acceleration is determi...

Ring rolling is one of the most significant methods for producing rings with highly precise dimensions and superior qualities such as high strength uniformity, all accomplished without wasting any materials. In this article, we have achieved analytical formulas for calculating the pressure and shear friction over the contact arcs between the rollers and ring in the ring rolling process for the ...

A constitutive model for the elastic-plastic behavior of plastically compressible orthotropic materials is proposed based on an ellipsoidal yield surface with evolving ellipticity to accommodate non-uniform hardening or softening associated with stressing in different directions. The model incorporates rate-dependence arising from material rate-dependence and micro-inertial effects. The basic i...

A 3-D numerical model for pulsed laser transformation hardening (LTH) is developed using the finite element method. In this model, laser spatial and temporal intensity distribution, temperature-dependent thermophysical properties of material, and multi-phase transformations are considered. The influence of laser temporal pulse shape on connectivity of hardened zone, maximum surface temperature ...

A study has been made on the parametric excitation of a nonlinear system with hardening springs. I n the parametric excitation of linear systems, the only subharmonic predicted i s a subharmonic of order 1/2. However, i n the parametric excitation of nonlinear systems, i t i s shown th I ? higher order subharmonics can exist, depending both on the amplitude and frequency of the parametric excit...

recently, a large amount of studies have been related to nonlinear systems with multi-degrees of freedom as well as continuous systems. the purpose of this paper is to optimize passive vibration absorbers in linear and nonlinear states for an euler-bernoulli beam with a nonlinear vibratory behavior under concentrated moving load. the goal parameter in the optimization is maximum deflection of t...

The Low Yield Strength Steel (LYS) has the superiority over long period of low cycle fatigue, high strain hardening rate and impressive ductility to overcome the local fracture problem existing in regular A36 steel plate. With elastoplastic characteristics and experimental verification, it becomes a good material considered for added damping and stiffness (ADAS) since the stress–strain relation...

In this paper, an elastoplastic constitutive model is presented for predicting sandy soil behavior under monotonic and cyclic loadings. The model is based on the CJS3 model that takes into account deviatoric and isotropic mechanisms of plasticity. The flow rule in deviatoric mechanism is non-associated and a kinematic hardening law controls the evolution of the yield surface. In the present s...

This paper presents a new formulation of a well known double hardening model often referred to as the Hardening Soil model. As an alternative to the existing Hardening Soil model’s Mohr-Coulomb failure surface, the new formulation allows for the incorporation of smooth failure surfaces, such as the failure surface proposed by Matsuoka & Nakai or that proposed by Lade & Duncan. Although the inco...

Using molecular dynamics simulations of a generic model, we observe strain hardening in highly cross-linked polymer glasses under tensile deformation. We show that formation of microvoids, without bond breaking, constitutes the microscopic origins of strain hardening. A well-defined functional form is observed for the void size distribution that is consistent with voids in dense equilibrium Len...