The mixed method for the biharmonic problem introduced in [12] is extended to the Reissner-Mindlin plate model. The Reissner-Mindlin problem is written as a system of first order equations and all the resulting variables are approximated. However, the hybrid form of the method allows one to eliminate all the variables and have a final system only involving the Lagrange multipliers that approxim...

This paper provides analytical insights into the hypothesis that fish exploit resonance to reduce the mechanical cost of swimming. A simple body-fluid fish model, representing carangiform locomotion, is developed. Steady swimming at various speeds is analysed using optimal gait theory by minimizing bending moment over tail movements and stiffness, and the results are shown to match with data fr...

Computer modelling and numerical FEM analysis of buried preloaded (prestressed) piping of a compressor station is shortly discussed in the present paper. The aim of the preloading is to reduce the stress intensity at the critical point of the piping. The necessary preloading force was computed as a non-linear function of the effects of bearing and friction at the pipe/soil interface. The real m...

A series of RANS-based aerodynamic shape optimization for an 800-passenger blended-wing-body aircraft is performed. A gradient-based optimization algorithm and a parallel structured multiblock RANS solver with Spalart–Allmaras turbulence model are used. The derivatives are computed using a discrete adjoint method considering both frozen-turbulence and full-turbulence assumptions. A total of 274...

This paper investigates the natural frequency, steady-state resonance and stability for the transverse vibrations of a nanobeam subjected to a variable initial axial force, including axial tension and axial compression, based on nonlocal elasticity theory. It is reported that the nonlocal nanoscale has significant effects on vibration behavior, which results in a new effective nonlocal bending ...

Abstract-A plate with a pre-existent through crack is considered under the action of a remote bending moment and a remote in-plane force. The problem statement is reduced to the solution of two coupled integral equations with strongly singular kernels. The independent variables in the latter equations are the closure displacement and rotation angle. The corresponding closure force and moment di...

Introduction Fatigue is the structural damage that leads the components of a wind turbine to sudden brittle failure when it suffers cyclic loading [15]. As the size of wind turbines is growing, fatigue loads become more and more significant for the design of major structural components. Concerning fatigue in a wind turbine tower, the fore-aft tower foot bending moment is considered as the most ...