The present paper deals with experimental and nonlinear finite element analysis of sandwich T-joints which are formed by two panels connected by lap joints. Such joints are for instance commonly used in high-speed marine vehicles, and the joints considered herein are typical for such structures. This study is concerned with T-joints subjected to tension (pull-out) force and the behaviour up to ultimate failure. The behaviour of such sandwich joints is very complex, since it involves several types of materials such as GRP, glue filler as well as foam material, and a geometry with potential high stress concentrations. Also, nonlinear material and geometrical effects may influence the ultimate behaviour. In this study experimental specimens have been produced and tested to failure. A nonlinear finite element method is adopted throughout the T-joint, which is taking into account the possible high-stress concentration positions, the nonlinear properties of both the core and the glue materials and the nonlinear displacement deformation of the T-joint. In this way we succeeded in making a significant contribution to furthering the understanding of the response and failure of sandwich T-joints. The effect of some design parameters of such joints affecting joint strength and flexibility is also investigated.

The study of wave action on large, elastic floating bodies has received considerable attention, finding applications in both geophysics and marine engineering problems. In this context, a higher order finite-element method (FEM) for the numerical simulation of the transient response of thin, floating bodies in shallow water wave conditions is presented. The hydroelastic initial-boundary value problem, in an inhomogeneous environment, characterized by bathymetry and plate thickness variation, is analysed for two configurations: (i) a freely floating strip modelling an ice floe or a very large floating structure and (ii) a semi-fixed floating beam representing an ice shelf or shore fast ice, both under long-wave forcing. The variational formulation of these problems is derived, along with the energy conservation principle and the weak solution stability estimates. A special higher order FEM is developed and applied to the calculation of the numerical solution. Results are presented and compared against established methodologies, thus validating the present method and illustrating its numerical efficiency. Furthermore, theoretical results concerning the energy conservation principle are verified, providing a valuable insight into the physical phenomenon investigated.

Reactions. -A relatively inexpensive catalyst easily prepared from L-valine is applied to asymmetric aldol and cross-aldol reactions [reaction of (VI)]. The reaction proceeds with excellent stereoselectivity under mild, environmentally friendly conditions. Noteworthy, the aldol reaction occurs at the less-hindered face of the enamine in contrast to the cross-aldol reaction. -(TANIMURA, Y.; YASUNAGA, K.; ISHIMARU*, K.; Eur.

This paper examines the non-linear deflection response of highly stressed sandwich T-joints using large deflection and plasticity analyses. The finite element method considering a plane model of the joint, accounts for plastic deformation of the core and glue materials and non-linear geometric effects. The finite element studies are used to identify internal stress states in the various regions of the joint and for different attachment configurations, leading up to and at failure. The results of this analysis have been combined with the measured properties of the materials forming the joint in order to predict quantitatively the failure strength.

From the biharmonic equation of the plane problem in the polar coordinate system and taking into account the variable-separable form of the partial solutions, a homogeneous ordinary differential equation (ODE) of the fourth order is deduced. Our study is based on the investigation of the behavior of the coefficients of the above fourth order ODE, which are functions of the radial coordinate r. According to the proposed investigation additional terms, φ¯−m(r,θ)(1≤m≤n) other than the usually tabulated in the Michell solution (1899, “On the Direct Determination of Stress in an Elastic Solid, With Application to the Theory of Plates,” Proc. Lond. Math. Soc., 31, pp. 100–124) are found. Finally the stress and the displacement fields due to each one additional term of φ¯−m(r,θ) are determined.