RETRACTED: Triality theory and complete post-buckling solutions of large deformed beam by canonical dual finite element method

2015 ◽  
Vol 21 (3) ◽  
pp. NP121-NP122
Author(s):  
Kun Cai ◽  
David Y Gao ◽  
Qing H Qin
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Triality Theory ◽  
Post Buckling ◽  
Element Method

A numerical approach based on finite element method for the wrinkling analysis of dielectric elastomer membranes

2021 ◽  
pp. 1-37
Author(s):  
Guoyong Mao ◽  
Wei Hong ◽  
Martin Kaltenbrunner ◽  
Shaoxing Qu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Thickness Distribution ◽  
Numerical Approach ◽  
Dielectric Elastomer ◽  
Equivalent Model ◽  
Maxwell Stress ◽  
Buckling Mode ◽  
Post Buckling ◽  
Element Method

Abstract Dielectric elastomer (DE) actuators are deformable capacitors capable of a muscle-like actuation when charged. When subjected to voltage, DE membranes coated with compliant electrodes may form wrinkles due to the Maxwell stress. Here, we develop a numerical approach based on the finite element method (FEM) to predict the morphology of wrinkled DE membranes mounted on a rigid frame. The approach includes two steps, I) pre-buckling and II) post-buckling. In step I, the first buckling mode of the DE membrane is investigated by substituting the Maxwell stress with thermal stress in the built-in function of the FEM platform SIMULIA Abaqus. In step II, we use this first buckling mode as an artificial geometric imperfection to conduct the post-buckling analysis. For this purpose, we develop an equivalent model to simulate the mechanical behavior of DEs. Based on our approach, the thickness distribution and the thinnest site of the wrinkled DE membranes subjected to voltage are investigated. The simulations reveal that the crests/troughs of the wrinkles are the thinnest sites around the center of the membrane and corroborate these findings experimentally. Finally, we successfully predict the wrinkles of DE membranes mounted on an isosceles right triangle frame with various sizes of wrinkles generated simultaneously. These results shed light on the fundamental understanding of wrinkled dielectric elastomers but may also trigger new applications such as programmable wrinkles for optical devices or their prevention in DE actuators.

The Strain Energy Tuning of the Shape Memory Alloy on the Post-Buckling of Composite Plates Using Finite Element Method

2012 ◽  
Vol 445 ◽  
pp. 577-582
Author(s):  
Zainudin A. Rasid ◽  
Saiful Amri Mazlan ◽  
Amran Ayob ◽  
Rizal Zahari ◽  
Dayang Laila Majid ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Strain Energy ◽  
Composite Plates ◽  
Post Buckling ◽  
Energy Tuning ◽  
Element Method

scholarly journals Effect of Semi-Rigid Connection on Post-Buckling Behaviour of Frames Using Finite Element Method

2019 ◽  
Vol 5 (7) ◽  
pp. 1619-1630
Author(s):  
Douaa Raheem Mohammed ◽  
Murtada A. Ismael
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Peak Load ◽  
Joint Stiffness ◽  
Structural Behaviour ◽  
Beam Columns ◽  
Analysis And Design ◽  
Rigid Connection ◽  
Post Buckling ◽  
Element Method

It is very important task to estimate the post buckling for structures that have slender elements, since post-buckling state means loss the structures stability related with large displacement and that lead to demolition the structures. On the other hand, in the design and analysis of steel frame, the beam-columns connection is assumed perfect pin or fully rigid, this assumption leads to incorrect estimation of the structural behaviour. Practically, beam-column connection is between these two assumptions and this type of connection is called semi-rigid. This study presents a numerical analysis using finite element method to investigate the effect of semi-rigid connections on post-buckling behaviour of two-dimensional frames with different supporting types and different lateral loading cases. The semi-rigid connections are modelled as rotational spring in linear elastic stage, using COMBIN14 element which has rotational stiffness value.  The numerical results showed that; the effect of changing the beam-column connections from rigid to semi rigid for toggle frame with rotational joint stiffness 25EI/L to 15EI/L and 10EI/L led to decrease the initial peak load of the frames of fixed-fixed supports with percentages 3.36 %, 5.6% and 8.95% respectively as compared with that of the rigid connection frame, While, the frames with fixed-pin and pin-pin supports cases did not affected by this changing. The fixed-fixed support case is more affected by changing the joint stiffness from other cases and the effect of changing the joint stiffness in pin-pin support model is less significant from others. This can be attributed to that, the fixed-fixed supports is restrained in all degree of freedom and will be affected by any rotation and presence the pin in other cases makes the frame less affected by the rotation of semi-rigid connection. The effect of changing the beam-column connection from rigid to semi rigid decreases with presence the lateral load. Thus, the semi-rigid connection should be considered in analysis and design of steel frames to obtain more realistic results.

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