A finite element model is proposed to study the stresses in the neighborhood of a cylinder-cylinder intersection. In particular, diameter ratios greater than 0.5 are focused upon since little information is available in the ASME Boiler and Pressure Vessel Code or in the literature about the stress concentration for these geometries. The aim of the present work is to validate such a model for internal pressure loading. To accomplish this, various parametric finite element studies were conducted. The selected model is then validated by applying it to various available cylinder intersection models and comparing the results. The finite element results are further compared with a solution obtained using a shell theory.

A series of plate elements, based on the modified complementary energy principal, are developed to study the free undamped vibration response of laminated composite plates. The Mindlin thin plate theory is selected to govern the general characteristics and behavior of these plate elements. A series of in-plane strain functions are assumed from which the corresponding in-plane strains and corresponding stresses for each lamina are determined. The transverse stresses are then computed by satisfying the equations of the equilibrium. Eight-noded isoparametric elements are utilized to describe the displacement field. These hybrid plate elements are used to form the stiffness and the consistent mass matrices. The fundamental natural frequencies are then computed by solving the generalized eigenvalue problem and their application demonstrated via a number of examples. [S0094-9930(00)02603-7]

The use of the asymptotic expansion technique when applied to the three-dimensional elasticity equations is outlined and used to demonstrate the development of an asymptotic beam theory and associated boundary conditions. The formulation thus obtained holds for arbitrary cross section shapes and is applied here to pipes. It can be used to provide benchmark solutions to test the suitability of engineering beam and shell theories.

Multilayered composite plates are of interest for a variety of structural applications in such industries as automotive and aerospace, where high strength-to-weight ratios are desirable. In this investigation a series of plate elements is developed for such structures. These plate elements are formulated based on a variational principle, namely modified complementary energy. Mindlin thin plate theory is selected to govern the general characteristics and behavior of these plates. Transverse shear deformation is included in the formulation. A series of in-plane strain functions is assumed from which the corresponding in-plane stresses for each lamina are determined. By satisfying the equilibrium equations, the transverse stresses are calculated. The strain parameters can be determined by satisfying the interlaminar transverse stress continuity and the traction-free condition at the bottom surface. The top traction-free condition is ignored in this formulation. It will be demonstrated that the impact of ignoring the top traction-free condition on the results is negligible.Eight-node isoparametric elements with five degrees of freedom per node are utilized to describe the displacement field. These elements are invariant, fast converging, and insensitive to the number of gauss points used in the numerical integrations. Moreover, it will be shown that these elements do not exhibit any shear locking in the thin plate limit. These elements are capable of handling the effects of transverse shear deformation, extensionbending, twisting-extension, and twisting-bending coupling that exist due to the different orthotropic material properties of each layer. It will also be demonstrated that these elements are capable of adequately predicting the displacements and the stresses for a variety of composite plate problems.

The development of efficient, energy‐saving, and automated manufacturing of free‐form variable‐thickness polymer composite components has created a step‐change and enabled technology for the composites industry seeking geometry tailoring during a mould‐less and/or additive manufacturing such as that in 3D printing. The current article presents research on magnetic field assisted 3D printing of iron particles‐embedded thermoplastic polylactic acid, during a fused deposition method based 3D printing. The magnets are symmetrically fixed on both sides of the printed nanocomposite. The setup utilised Neodymium magnets with a constant strength below one Tesla. Observations have shown that the nanocomposites being printed undergo permanent macro‐scale deformations due to the extrinsic strains induced by the iron particles' magnetisation. To provide a theoretical understanding of the induced strains, a Multiphysics constitutive equation has been developed. The evolution of magnetisation within a relatively thick nanocomposite (5 mm thickness) has been studied. A correlation has been established between the extrinsic strains from the experimental data and the theoretical solution. The theory exhibits an accurate description of the field‐induced strains provided that real‐time temperatures for the printed layers are accounted for. The results demonstrate a viable and disruptive magnetic field‐equipped fabrication with ability for permanent geometry control during a process.