scholarly journals MANIPULATION OF EIGENVALUES OF A STIFFNESS MATRIX FOR AN ELASTO-PLASTIC ANALYSIS INCLUDING INSTABILITY

2021 ◽  
Vol 86 (790) ◽  
pp. 1607-1614
Author(s):  
Akio HORI ◽  
Arisa EJIMA
Keyword(s):  
Stiffness Matrix ◽  
Plastic Analysis

Elasto-Plastic Analysis of Frame Structures under Large Displacement-Rotation Deformations

2011 ◽  
Vol 243-249 ◽  
pp. 5968-5974
Author(s):  
Dong Quan Yang ◽  
Hong Peng
Keyword(s):  
Finite Element ◽  
Stiffness Matrix ◽  
Control Method ◽  
Large Displacement ◽  
Frame Structures ◽  
Finite Element Program ◽  
Numerical Experimentation ◽  
Plastic Analysis ◽  
Element Program ◽  
Displacement Control Method

A finite element program for elasto-plastic analysis of 3D beams and frame structures under large displacement/rotations is developed. The element is Timoshenko beam element based on mechanics of continuum. Constitutive equations for large displacements/rotations in elastic stage are expressed in an explicit way which is suitable for programming. The modification of constitutive equation is presented for the analysis of elasto-plastic problems. A fiber model is adopted for the calculation of stiffness matrix and internal forces. For solution of nonlinear finite element equations, general displacement control method and semi-modified stiffness matrix method is adopted. The results of numerical experimentation show that the program work well for 3D beams and frame structures under elasto-plastic large displacement/rotations.

Plastic analysis of complex microstructure composites using the generalized method of cells

AIAA Journal ◽  
1999 ◽  
Vol 37 ◽  
pp. 482-488 ◽  
Author(s):  
Carlos E. Orozco ◽  
Marek-Jerzy Pindera
Keyword(s):  
Plastic Analysis ◽  
Generalized Method Of Cells

Computational issues for two multiple constraint stiffness matrix adjustment methods

1995 ◽  
Author(s):  
Kyle Dippery ◽  
Suzanne Smith ◽  
Zhaojun Bai
Keyword(s):  
Stiffness Matrix ◽  
Multiple Constraint

A Computer-Aided System for Automatic Mitosis Detection from Breast Cancer Histological Slide Images based on Stiffness Matrix and Feature Fusion

2015 ◽  
Vol 10 (4) ◽  
pp. 476-493 ◽  
Author(s):  
Ashkan Tashk ◽  
Mohammad Sadegh Helfroush ◽  
Habibollah Danyali ◽  
Mojgan Akbarzadeh
Keyword(s):  
Breast Cancer ◽  
Stiffness Matrix ◽  
Feature Fusion ◽  
Mitosis Detection ◽  
Computer Aided ◽  
Histological Slide

Physical Ultrasonics of Composites

2011 ◽  
Author(s):  
Dale Chimenti ◽  
Stanislav Rokhlin ◽  
Peter Nagy
Keyword(s):  
Composite Laminates ◽  
Stiffness Matrix ◽  
Composite Plates ◽  
Anisotropic Media ◽  
Anisotropic Materials ◽  
Ultrasonic Waves ◽  
Laminated Plates ◽  
Structure Characteristic ◽  
Major Advance

Physical Ultrasonics of Composites is a rigorous introduction to the characterization of composite materials by means of ultrasonic waves. Composites are treated here not simply as uniform media, but as inhomogeneous layered anisotropic media with internal structure characteristic of composite laminates. The objective here is to concentrate on exposing the singular behavior of ultrasonic waves as they interact with layered, anisotropic materials, materials which incorporate those structural elements typical of composite laminates. This book provides a synergistic description of both modeling and experimental methods in addressing wave propagation phenomena and composite property measurements. After a brief review of basic composite mechanics, a thorough treatment of ultrasonics in anisotropic media is presented, along with composite characterization methods. The interaction of ultrasonic waves at interfaces of anisotropic materials is discussed, as are guided waves in composite plates and rods. Waves in layered media are developed from the standpoint of the "Stiffness Matrix", a major advance over the conventional, potentially unstable Transfer Matrix approach. Laminated plates are treated both with the stiffness matrix and using Floquet analysis. The important influence on the received electronic signals in ultrasonic materials characterization from transducer geometry and placement are carefully exposed in a dedicated chapter. Ultrasonic wave interactions are especially susceptible to such influences because ultrasonic transducers are seldom more than a dozen or so wavelengths in diameter. The book ends with a chapter devoted to the emerging field of air-coupled ultrasonics. This new technology has come of age with the development of purpose-built transducers and electronics and is finding ever wider applications, particularly in the characterization of composite laminates.

Consistent co-rotational framework for Euler-Bernoulli and Timoshenko beam-column elements under distributed member loads

2021 ◽  
pp. 136943322098663
Author(s):  
Yi-Qun Tang ◽  
Wen-Feng Chen ◽  
Yao-Peng Liu ◽  
Siu-Lai Chan
Keyword(s):  
Coordinate System ◽  
Stiffness Matrix ◽  
Traditional Method ◽  
Local Coordinate System ◽  
Frame Structures ◽  
Global Coordinate System ◽  
Single Element ◽  
Geometrically Nonlinear ◽  
Geometrically Nonlinear Analysis ◽  
Geometric Stiffness

Conventional co-rotational formulations for geometrically nonlinear analysis are based on the assumption that the finite element is only subjected to nodal loads and as a result, they are not accurate for the elements under distributed member loads. The magnitude and direction of member loads are treated as constant in the global coordinate system, but they are essentially varying in the local coordinate system for the element undergoing a large rigid body rotation, leading to the change of nodal moments at element ends. Thus, there is a need to improve the co-rotational formulations to allow for the effect. This paper proposes a new consistent co-rotational formulation for both Euler-Bernoulli and Timoshenko two-dimensional beam-column elements subjected to distributed member loads. It is found that the equivalent nodal moments are affected by the element geometric change and consequently contribute to a part of geometric stiffness matrix. From this study, the results of both eigenvalue buckling and second-order direct analyses will be significantly improved. Several examples are used to verify the proposed formulation with comparison of the traditional method, which demonstrate the accuracy and reliability of the proposed method in buckling analysis of frame structures under distributed member loads using a single element per member.

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