Transient Response Analysis of Geometrically Nonlinear Laminated Composite Shell Structures

1996 ◽  
Author(s):  
Cho W. S. To ◽  
Bin Wang
Keyword(s):  
Finite Element ◽  
Degrees Of Freedom ◽  
Composite Shell ◽  
Laminated Composite ◽  
Shell Structures ◽  
Response Analysis ◽  
Hybrid Strain ◽  
Drilling Degree Of Freedom ◽  
Shell Finite Element ◽  
Shear Deformable

Abstract The investigation reported in this paper is concerned with the prediction of geometrically large nonlinear responses of laminated composite shell structures under transient excitations by employing the hybrid strain based flat triangular laminated composite shell finite element presented here. Large deformation of finite strain and finite rotation are considered. The finite element has eighteen degrees-of-freedom which encompass the important drilling degree-of-freedom at every node. It is hinged on the first order shear deformable lamination theory. Various laminated composite shell structures have been studied and for brevity only two are presented here. It is concluded that the element proposed is very accurate and efficient. Shear locking has not appeared in the results obtained thus far. There is no zero energy mode detected in the problems studied. For nonlinear dynamic response computations, the full structural system has to be considered if accurate results are required.

Nonstationary Random Response of Laminated Composite Structures by a Hybrid Strain-Based Laminated Flat Triangular Shell Finite Element

1995 ◽  
Author(s):  
C. W. S. To ◽  
B. Wang
Keyword(s):  
Finite Element ◽  
Composite Structures ◽  
Composite Shell ◽  
Laminated Composite ◽  
Random Excitation ◽  
Cylindrical Panel ◽  
Shell Structures ◽  
Hybrid Strain ◽  
Automobile Engineering ◽  
Shell Finite Element

Abstract The prediction and analysis of response of laminated composite shell structures under nonstationary random excitation is of considerable interest to design engineers in aerospace and automobile engineering fields. However, it seems that there is no known comprehensive published work on such an analysis that employs the versatile finite element method. Thus, the main focus of the investigation reported in this paper is the application of the hybrid strain-based laminated composite flat triangular shell finite element, that has been developed by the authors, for the analysis of laminated composite shell structures under a relatively wide class of nonstationary random excitations. Representative results of a simply-supported laminated composite cylindrical panel subjected to a point nonstationary random excitation are included.

Optimal Control of Random Vibration in Shell Structures With Embedded Piezoelectric Components

2005 ◽  
Author(s):  
Cho W. S. To ◽  
Tao Chen
Keyword(s):  
Finite Element ◽  
Random Vibration ◽  
Degrees Of Freedom ◽  
Large Scale ◽  
Shell Structures ◽  
Engineering System ◽  
Hybrid Strain ◽  
Strain Formulation ◽  
Shell Panel ◽  
Shell Finite Element

The state covariance assignment (SCA) method of Skelton and associates is applied in the present investigation to the optimal random vibration control of large scale complicated shell structures with embedded piezoelectric components. It provides a direct approach for achieving performance goals stated in terms of the root-mean-square (RMS) values which are common in many engineering system designs. The large scale shell structures embedded with piezoelectric components of complicated geometrical configurations are approximated by the hybrid strain or mixed formulation based lower order triangular shell finite element developed in the present investigation. This shell finite element has three nodes every one of which has seven degrees of freedom (dof). The latter include three translational dof, three rotational dof, and one electric potential dof. The element is a better alternative to those based on the displacement formulation and that hinged on the truly hybrid strain formulation. Representative results applying the SCA method for a shell panel embedded with piezoelectric components are included to demonstrate its simplicity of use and efficiency of implementing the proposed approach.

An Edge-Based Smoothed MITC3 (ES-MITC3) Shell Finite Element in Laminated Composite Shell Structures Analysis

2018 ◽  
Vol 15 (07) ◽  
pp. 1850060 ◽  
Author(s):  
Quoc-Hoa Pham ◽  
The-Van Tran ◽  
Tien-Dat Pham ◽  
Duc-Huynh Phan
Keyword(s):  
Finite Element ◽  
Composite Shell ◽  
Laminated Composite ◽  
Shear Stiffness ◽  
Shell Structures ◽  
Simple Modification ◽  
Virtual Plane ◽  
Triangular Elements ◽  
Shell Finite Element ◽  
Edge Based

This paper proposes an improvement of the MITC3 shell finite element to analyze of laminated composite shell structures. In order to enhance the accuracy and convergence of MITC3 element, an edge-based smoothed finite element method (ES-FEM) is applied to the derivation of the membrane, bending and shear stiffness terms of the MITC3 element, named ES-MICT3. In the ES-FEM, the smoothed strain is calculated in the domain that constructed by two adjacent MITC3 triangular elements sharing an edge. On a curved geometry of shell models, two adjacent MITC3 triangular elements may not be placed on the same plane. In this case, the edge-based smoothed strain can be performed on the virtual plane based on strain transformation matrices between the global coordinate and this virtual coordinate. Furthermore, a simple modification coefficient is chosen to be [Formula: see text] times the maximum diagonal value of the element stiffness matrix at the zero drilling degree of freedom to avoid the drill rotation locking when all elements meeting at a node are coplanar. The numerical examples demonstrated that the proposed method achieves the high accuracy in comparison to others existing elements in the literature.

scholarly journals Finite Element Vibration Analysis of Laminated Composite Folded Plate Structures

1999 ◽  
Vol 6 (5-6) ◽  
pp. 273-283 ◽  
Author(s):  
A. Guha Niyogi ◽  
M.K. Laha ◽  
P.K. Sinha
Keyword(s):  
Finite Element ◽  
Forced Vibration ◽  
Vibration Analysis ◽  
Degrees Of Freedom ◽  
Laminated Composite ◽  
Mode Shapes ◽  
Plate Structures ◽  
Drilling Degree Of Freedom ◽  
Vibration Responses ◽  
Forced Vibration Analysis

A nine-noded Lagrangian plate bending finite element that incorporates first-order transverse shear deformation and rotary inertia is used to predict the free and forced vibration response of laminated composite folded plate structures. A 6 × 6 transformation matrix is derived to transform the system element matrices before assembly. The usual five degrees-of-freedom per node is appended with an additional drilling degree of freedom in order to fit the transformation. The present finite element results show good agreement with the available semi-analytical solutions and finite element results. Parametric studies are conducted for free and forced vibration analysis for laminated folded plates, with reference to crank angle, fibre angle and stacking sequence. The natural frequencies and mode shapes, and forced vibration responses furnished here may serve as a benchmark for future investigations.

Large Nonlinear Random Responses of Spatially Non-Homogeneous Stochastic Shell Structures

2006 ◽  
Author(s):  
C. W. S. To
Keyword(s):  
Finite Element ◽  
Random Excitation ◽  
Shell Structures ◽  
Response Analysis ◽  
Hybrid Strain ◽  
Central Difference ◽  
Approximation Techniques ◽  
Nonlinear Responses ◽  
Random Disturbances ◽  
Excitation Processes

This paper is concerned with large nonlinear random response analysis of spatially non-homogeneous stochastic shell structures under transient excitations. The latter are treated as nonstationary random excitation processes. The emphases are on (i) spatially non-homogeneous and homogeneous stochastic shell structures with large spatial variations, (ii) large nonlinear responses with finite strains and finite rotations, and (iii) intensive nonstationary random disturbances. The shell structures are approximated by the lower order mixed or hybrid strain based triangular shell finite elements developed earlier by the author and his associate. The nonstationary random nonlinear responses are evaluated by a procedure that consists of the stochastic central difference method, time co-ordinate transformation, and modified adaptive time scheme. Computationally, the procedure is very efficient compared with those entirely and partially based on Monte Carlo simulation, and is free from the limitations associated with those employing perturbation approximation techniques, such as the so-called stochastic finite element or probabilistic finite element method.

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