Four-Node Quadrilateral Element with Continuous Nodal Stress for Geometrical Nonlinear Analysis

In this paper, the performance of a hybrid ‘FE-Meshfree’ quadrilateral element with continuous nodal stress (Quad4-CNS) is investigated for geometrical nonlinear solid mechanic problems. By combining finite element method (FEM) and meshfree method, this Quad4-CNS synergizes the individual strengths of these two methods, which leads to higher accuracy, better convergence rate, as well as high tolerance to mesh distortion. Therefore, Quad4-CNS is attractive for geometrical nonlinear solid mechanic problems where excessive distorted meshes occur. For geometrical nonlinear analysis, numerical results show that the results of Quad4-CNS element are much better than those of four-node isoparametric quadrilateral element (Quad4), and are comparable to quadratic quadrilateral element (Quad8) and other hybrid ‘FE- Meshfree’ elements.

Influence of Masonry Properties on Confinement: A Mechanical Model

Design provisions for the repair, retrofitting, and rehabilitation of existing masonry structures are not always available and included in International and National Building Codes. Due to the extremely large variability in masonry performances, equations of general validity cannot be provided, namely relationships suitable for confinement of every masonry type, as it is done for concrete. Large amount of results obtained for concrete led to consolidated design guidelines. Despite the great research effort in the experimental field on masonry, considerable theoretical work is still needed to fully outline a definitive analytical model to predict the behavior of FRP confined masonry. In this study, a mechanically based confinement model is proposed based on mechanical parameters able to differentiate similar masonry types and to highlight that they present different confinement performance. The most relevant parameters are the compressive and tensile strength of unconfined masonry and they are discussed in the framework of solid mechanic based models based on triaxial plasticity and calibrated experimentally. The proposed approach can then be extended to other masonry types.

Interfacing PATRAN or ANSYS Programs to FIDAP for Analysis of Realistic Engineering Problems

With the recent advances in the various fields of engineering and the fields of computer hardware and software, a large number of computer programs are being used as design tools in the area of manufacturing. These tools generally deal with parameters and variables specific to one particular area. For instance, a solid mechanic code is equipped with means of specifying forces and displacements and a program designed for magnetics analysis can only have input/output related to magnetics. However, in many realistic systems, a number of these various fields are present and effective design requires coupling of these variables.

Optimal Shape Design of Turbine Blades

This paper attempts to present a general engineering method for minimizing the weight of rotating turbine blades in optimizing the cross section shapes. The constraints originate from either aerodynamic or solid mechanic specifications. As the problem is reformated after a first F.E. analysis, the optimization process is quite inexpensive. A large variety of compressor or turbine rotating blades can be designed by this method which uses the variables selected by the aerodynamicists and leads to continuous optimal profiles.