In this paper, we propose an iterative beam hardening correction method that is applicable for the case with multiple materials. By assuming that the materials composing scanned object are known and that they are distinguishable by their linear attenuation coefficients at some given energy, the beam hardening correction problem is converted into a nonlinear system problem, which is then solved ...

Control-based continuation (CBC) is a means of applying numerical continuation directly to a physical experiment for bifurcation analysis without the use of a mathematical model. CBC enables the detection and tracking of bifurcations directly, without the need for a post-processing stage as is often the case for more traditional experimental approaches. In this paper, we use CBC to directly loc...

This paper explores the vibration damping properties of thermal barrier coatings (TBCs) containing thin plastically deformable metallic layers embedded in an elastic ceramic matrix. We develop an elastic–plastic dynamical model to study how work hardening, yield strain, and elastic modulus of the metal affect the macroscopic damping behavior of the coating. Finite element (FE) simulations valid...

The construction of regularization operators presented in this work is based on the introduction of strain or damage micromorphic degrees of freedom in addition to the displacement vector and of their gradients into the Helmholtz free energy function of the constitutive material model. The combination of a new balance equation for generalized stresses and of the micromorphic constitutive equati...

An inverse coefficient problem related to identification of the plasticity function g(η) from a given torque τ is studied for a circular section bar. Within the deformation theory of plasticity the mathematical model of torsion leads to the nonlinear Dirichlet problem −∇ · (g(|∇u|2)∇u) = 2φ, x ∈ Ω ⊂ R2; u(s) = 0, s ∈ ∂Ω . For determination of the unknown coefficient g(η) ∈ G, an integral of the...

This paper analyses the influence of residual stresses and strain hardening due to the cold rollforming process on the load carrying capacity of perforated rack columns. First of all, a residual strain distribution of the manufacturing process is obtained via a finite element analysis and then it is introduced in the model as initial state to carry out a nonlinear buckling analysis. Two differe...

We use a modified filament stretching rheometer to quantify the influence of a known controlled pre-shear history on the transient extensional viscosity of a dilute polymer solution. Two different types of pre-deformation are explored; both influence the subsequent stretching significantly, albeit in opposite ways. Small-amplitude oscillatory straining parallel to the direction of stretching en...

We propose an algorithm for the efficient parallel implementation of elastoplastic problems with hardening based on the so-called TFETI (Total Finite Element Tearing and Interconnecting) domain decomposition method. We consider an associated elastoplastic model with the von Mises plastic criterion and the linear isotropic hardening law. Such a model is discretized by the implicit Euler method i...

in the present study, the mechanical behavior of aa5052 aluminum alloy during cold deformation and subsequent isothermal annealing in a temperature range of 225-300oc was investigated using the uniaxial tensile test data. it is found that by increasing the annealing time and temperature the material yield strength is decreased. the microstructural investigations of the annealed samples show tha...

In computed tomography (CT), the nonlinear attenuation characteristics of polychromatic X-rays cause beam hardening artifacts in the reconstructed images. State-of-theart methods to correct the beam hardening effect are mostly single material precorrections (e.g. water-precorrection), which are far less efficient when more than one material is present in the field of measurement. The use of tho...