Convex resource allocation scheduling in the no-wait flowshop with common flow allowance and learning effect

We study the problem of two-machine no-wait flowshop scheduling with learning effect and convex resource-dependent processing times. Under the condition of the due-date assignment with common flow allowance (i.e. slack (SLK) due-date assignment), we provide a bi-criteria analysis where the first criterion is to minimise the scheduling criteria (i.e. the weighted sum of earliness, tardiness and flow allowance costs), and the second criterion is to minimise the resource consumption cost (i.e. the weighted sum of resource consumption cost). The objective is to determine the optimal job sequence, resource allocations and common (flow allowance) slack time that minimise the three different versions of the two criteria. We prove that these problems can be solved in polynomial time.     

Finite element method of thermal shock problem in a non-homogeneous isotropic hollow cylinder with two relaxation times

A solution of thermal shock problem of generalized thermoelasticity of a non-homogeneous isotropic hollow cylinder using finite element method is developed. Lord–Shulman and Green–Lindsay for the generalized thermoelasticity model are selected for that purpose which reduces to the classical model by appropriate choice of the parameters. The problem has been solved numerically using a finite element method (FEM). Numerical results for the temperature distribution, displacement, radial stress and hoop stress are represented graphically. The results indicate that the effects of nonhomogeneity are very pronounced. The effects of nonhomogeneity is presented with the three theories.     

Modal numerical–experimental identification method for characterising the elastic and damping properties in sandwich structures with a relatively stiff core

In this paper, a mixed numerical–experimental identification procedure for characterising the storage and loss properties in sandwich structures with a relatively stiff core is developed. At the computational level, the proposed method is based upon an original structurally damped shell finite element model derived from the higher-order shear deformation theory and, at the experimental level, upon an accurate contact-free measurement setup with a loudspeaker-based excitation and a scanning laser interferometer for capturing the time responses. From the modal information extracted from two specimens with different geometries, the procedure allows the simultaneous estimation of the skin and core constitutive parameters through adequate objective functions measuring the discrepancy between the experimental data and the numerical predictions. For validation purposes, the method is then applied to two test cases for which all the influent properties could be estimated with a fairly good accuracy.