Simple and economical procedures for large-deformation elasto-plastic analysis of frames, whose members can be characterized as beams, are presented. An assumed stress approach is employed to derive the tangent stiffness of the beam, subjected in general to non-conservative type distributed loading. The beam is assumed to undergo arbitrarily large rigid rotations but small axial stretch and rel...

It is a highly nonlinear problem of 3-D elastoplastic contact with friction. To obtain the key information about the real size, displacement and traction in contact zone, the elements in contact and plastic zone should be subdivided. However, the increase of degrees of freedom is limited by the problem-solving scale when traditional BEM is used, for a larger memory size is required and the solu...

In the context of nuclear waste disposal, the modelling of the behaviour of host rocks and soils still needs improvement. Unsaturated porous geomaterials exhibit particular behaviour when exposed to suction. Their non-linear behaviour may result from two different processes, plasticity which induces irreversible strains and damage which causes a deterioration of their elastic properties. Many e...

Abstract-In this paper, certain path-independent integrals, of relevance in the presence of cracks, in elastic and inelastic solids are considered. The hypothesized material constitutive properties include: (i) finite and infinitesimal elasticity, (ii) rate-independent incremental flow theory of elasto-plasticity, and (iii) ratesensitive behaviour including elasto-viscoplasticity and creep. In ...

Elasto fibroma dorsi is a rare tumour of the shoulder girdle that usually arises at the infra scapular area. We present a 57-year-old male with a soft tissue swelling on his right infra scapular area of 6 months duration. It was a painless lesion which caused him discomfort while sleeping. Preoperative imaging revealed bilateral tumours but the left tumour was impalpable. The surgery itself was...

Chalk is the constituent material of numerous oil reservoirs in North Sea. The mechanical behaviour of a saturated chalk has been largely studied. However, different aspects of its behaviour are not yet well understood: material characteristics depend on the saturating fluids and chalk response is timedependent. This paper proposes the PASACHALK numerical model: an elasto-plastic constitutive l...

In this paper some analytical and numerical aspects of time-dependent models with internal variables are discussed. The focus lies on elasto/visco-plastic models of monotone type arising in the theory of inelastic behavior of materials. This class of problems includes the classical models of elasto-plasticity with hardening and viscous models of the Norton-Hoff type. We discuss the existence th...

Abstract—In this paper, an analytical simplified method for calculating elasto-plastic stresses strains of notched bodies subject to non-proportional loading paths is discussed. The method was based on the Neuber notch correction, which relates the incremental elastic and elastic-plastic strain energy densities at the notch root and the material constitutive relationship. The validity of the me...

The techniques used in the fabrication of micro-electro-mechanical systems (MEMS) were adopted from the integrated circuits (IC) industry and are mostly limited to patterning thin films on a flat substrate. As a consequence, micro-machined devices mostly comprise sets of flat two-dimensional (2D) membranes with etched patterns and undercuts that enable them to serve their intended functions. Ho...

In this contribution, we deal with time-stepping schemes for geometrically nonlinear multiplicative elasto-plasto-dynamics. Thereby, the approximation in space as well as in time rely both on a Finite Element approach, providing a general framework which conceptually includes also higher-order schemes. In this context, the algorithmic conservation properties of the related integrators strongly ...