Finite Rotation Shells: Basic Equations and Finite Elements for Reissner Kinematics

ISBN-13: 9789048187607 / Angielski / Twarda / 2010 / 483 str.

K. Wisniewski

Opis

This book treats the formulation and finite elements for shells, and its subject is defined by the following topics:

1. Computational mechanics of non-linear shells,
2. Shell equations: Reissner kinematics, finite rotations, finite strains,
3. Shell finite elements: 4-node, enhanced or mixed or mixed/enhanced,
4. Drilling rotation: drilling Rotation Constraint or Allman shape functions,
5. Normal strain: recovered or parameterized,
6. Constitutive equations: incremental, plane stress or 3D.

A wide range of applications of shell elements implies that they should be versatile, i.e. account for finite rotations and strains, admit the incorporation of various constitutive laws and enable convenient linking with other elements. This is a serious challenge, which requires various aspects of the element's formulation to be very advanced.

The basic information on linear shell elements may be found in some textbooks on FEs, but this book contains several advanced topics related to non-linear shells, such as e.g. the parametrization of finite rotations, the methods of including the drilling rotation, various methods of treating the normal strain, and the enhanced as well as mixed and mixed/enhanced finite elements.

Some of these topics have been a subject of my research for years, and all the described methods have been implemented in my own elements, and tested. Therefore, I believe that my understanding of this complicated subject is correct and mature enough to be canned, and presented to others.

Recenzje

From the reviews:

"This outstanding, very important and useful book presets a modern continuum mechanics and mathematical framework to study the physical behaviours of shells, and to formulate and evaluate finite element procedures. ... The monograph is written in an accessible and self-contained manner. It will be of interest to mathematicians and engineers working in solid mechanics. Moreover, it would be good as a textbook for graduate courses in mechanics of elastic shells (specializing in shells, finite elements and applied numerical methods)." (Ján Lovísek, Mathematical Reviews, Issue 2012 g)

"The objective is to provide a comprehensive introduction to finite rotation shells and to nonlinear shell finite elements. The book is intended for both teaching and self-study, and emphasizes fundamental aspects and techniques of the subject. This book also contains several topics related to nonlinear shells such as the parametrization of finite rotations, the methods of inclusion of the drilling rotation, various methods of treating the normal strain, and the mixed finite elements." (V. Leontiev, Zentralblatt MATH, Vol. 1201, 2011)

Spis treści

Proviosional Table of contents (October 2009)

I PRELIMINARIES; 1 Introduction; 1.1 Subject of this book; 1.2 Notation; 2 Operations on tensors and their representations; 2.1 Cartesian bases; 2.2 Normal bases; 2.3 Gradients and derivatives; II SHELL EQUATIONS; 3 Rotations for 3D Cauchy continuum; 3.1 Polar decomposition of deformation gradient; 3.2 Rotation Constraint equation; 3.3 Interpretation of rotation Q; 3.4 Rate form of RC equation ; 3.5 Rotations calculated from the RC equation; 4 3D formulations with rotations; 4.1 Governing equations; 4.2 4-F formulation for nominal stress; 4.3 3-F formulation for nominal stress; 4.4 3-F and 2-F formulations for Biot stress; 4.5 3-F and 2-F formulations for 2nd Piola-Kirchhoff stress; 4.6 2-F formulation with unconstrained rotations; 5 Basic geometric definitions for shells; 5.1 Coordinates and position vector; 5.2 Basic geometric definitions; 5.3 Example: Geometrical description of cylinder; 6 Shells with Reissner kinematics and drilling rotation; 6.1 Kinematics; 6.2 Rotation Constraint for shells; 6.3 Shell strains; 6.4 Virtual work equation for shell; 6.5 Local shell equations; 6.6 Enhanced shell kinematics; 7 Shell-type constitutive equations; 7.1 Constitutive equations for 3D shells; 7.2 Reduced shell constitutive equations; 7.3 Shear correction factor; III FINITE ROTATIONS FOR SHELLS; 8 Parametrization of finite rotations; 8.1 Basic properties of rotations; 8.2 Parametrization of rotations; 8.3 Composition of rotations; 9 Algorithmic schemes for finite rotations; 9.1 Increments of rotation vectors in two tangent planes; 9.2 Variation of rotation tensor; 9.3 Algorithmic schemes for finite rotations; 9.4 Angular velocity and acceleration; IV FOUR-NODE SHELL ELEMENTS; 10 Basic relations for 4-node shell elements; 10.1 Bilinear isoparametric approximations; 10.2 Geometry and bases of shell element ; 10.3 Jacobian matrices; 10.4 Deformation gradient, F^TF and Q^TF products; 10.5 Numerical integration of shell elements; 10.6 Newton method and tangent operator; 11 Plane 4-node elements (without drilling rotation); 11.1 Basic equations; 11.2 Displacement element Q4; 11.3 Solution of FE equations for problems with additional variables; 11.4 Enhanced strain elements based on potential energy; 11.5 Mixed Hellinger-Reissner and Hu-Washizu elements; 11.6 Modification of F^TF product; 12 Plane 4-node elements with drilling rotation; 12.1 Basic relations for drill RC equation; 12.2 Difficulties in approximation of drill RC; 12.3 Implementation of drill RC in finite elements; 12.4 EADG method for formulations with rotations; 12.5 Mixed HW and HR functionals with rotations; 12.6 2D+drill elements for bi-linear shape functions; 12.7 2D+drill elements for Allman shape functions; 12.8 Numerical tests; 13 Modification of transverse shear stiffness of shell element; 13.1 Treatment of transverse shear stiffness of beams ; 13.2 Treatment of transverse shear stiffness of shell;  14 Warped 4-node shell element; 14.1 Definition of warpage ; 14.2 Warped element with modifications; 14.3 Substitute flat element and warpage correction; 14.4 Membrane locking of curved shell elements ; 14.5 Remarks on approximation of curved surfaces by 4-node elements ; V NUMERICAL EXAMPLES; 15 Numerical tests; 15.1 Characteristics of tested shell elements; 15.2 Elementary and linear tests; 15.3 Nonlinear tests; References; Author index; Subject Index

Blurb

This book covers theoretical and computational aspects of non-linear shells. Several advanced topics of shell equations and finite elements, not included in standard textbooks on finite elements, are addressed.

Key features include: several sets of 3D equations with the rotations introduced by either the polar decomposition equation or the rotation constraint equation; shell equations based on Reissner kinematics for finite rotations and strains, formulated in terms of different strains and stresses; a comprehensive account of finite rotations, including their properties and parameterization, as well as the algorithmic issues pertaining to rotation parameters; a comprehensive description and evaluation of several enhanced, mixed, and mixed/enhanced 4-node elements; a selection of useful remedies for such problems as: poor accuracy of in-plane shear strain, transverse shear locking, over-stiffening of warped elements, locking in sinusoidal bending, and deterioration of accuracy for extremely thin elements; a large set of numerical benchmarks for finite rotation shells; an extensive bibliography and comprehensive index.

Shells have been a subject of the author’s research for years, and all the methods described in the book have been implemented and tested in the field.

The book can be useful for graduate students, professional engineers, and researchers specializing in shells, Finite Elements and applied numerical methods.