Geometry-Driven Finite Element for Four-Dimensional Printing

2017 ◽  
Author(s):  
Tsz-Ho Kwok

Four-dimensional (4D) printing is a new category of printing that expands the fabrication process to include time as the forth dimension, and its process planning and simulation have to take time into consideration as well. The common tool to estimating the behavior of a deformable object is the finite element method (FEM). Although FEM is powerful, there are various sources of deformation from hardware, environment, and process, just to name a few, which are too complex to model by FEM. This paper introduces Geometry-Driven Finite Element (GDFE) as a solution to this problem. Based on the study on geometry changes, the deformation principles can be drawn to predict the relationship between the 4D-printing process and the shape transformation. Similar to FEM, the design domain is subdivided into a set of GDFEs, and the principles are applied on each GDFE, which are then assembled to a larger system that describes the overall shape. The proposed method converts the complex sources of deformation to a geometric optimization problem, which is intuitive and effective. The usages and applications of the GDFE framework have also been presented in this paper, including freeform design, reserve design, and design validation.

1973 ◽  
Vol 40 (1) ◽  
pp. 204-208
Author(s):  
R. W. McLay ◽  
E. M. Buturla

An optimization problem involving the thermal deflections of two parallel circular disks is examined. Error bounds are developed for both the finite-element solution and the optimization problem. The relationship between the errors is illustrated in a single bound.


Author(s):  
Tsz-Ho Kwok ◽  
Yong Chen

Four-dimensional (4D) printing is a new category of printing that expands the fabrication process to include time as the fourth dimension, and its simulation and planning need to take time into consideration as well. The common tool for estimating the behavior of a deformable object is the finite element method (FEM). However, there are various sources of deformation in 4D printing, e.g., hardware and material settings. To model the behavior by FEM, a complete understanding of the process is needed and a mathematical model should be established for the structure–property–process relationship. However, the relationship is usually complicated, which requires different kinds of testing to formulate such models due to the process complexity. With the insight that the characteristic of shape change is the primary focus in 4D printing, this paper introduces geometry-driven finite element (GDFE) to simplify the modeling process by inducing deformation behavior from a few physical experiments. The principle of GDFE is based on the relationship between material structure and shape transformation. Accordingly, a deformation simulation can be developed for 4D printing by applying the principles to the GDFEs. The GDFE framework provides an intuitive and effective way to enable simulation and planning for 4D printing even when a complete mathematical model of new material is not available yet. The use of the GDFE framework for some applications is also presented in this paper.


2016 ◽  
Vol 4 (1) ◽  
pp. 0-0
Author(s):  
Олег Ещенко ◽  
Oleg Eshchenko ◽  
Игорь Болгов ◽  
Igor Bolgov

In this article an example of Tuapse refinery examines the relationship deformations tank foundation and pile retaining structures at various embodiments, the construction of both objects. The finite element method determined the effect of tech-energy building by the amount of heel tank. Advice on selecting the best option erection paired structures


1974 ◽  
Vol 41 (1) ◽  
pp. 269-272 ◽  
Author(s):  
E. M. Buturla ◽  
R. W. McLay

Results of a numerical analysis completed in conjunction with the analytical development of a previous work are presented. The problem is an optimization study involving the thermal deflections of two parallel circular disks. The capability of choosing a mesh refinement to arbitrarily reduce approximation errors is illustrated and numerical convergence of the optimization process is demonstrated.


2015 ◽  
Vol 2015 ◽  
pp. 1-8
Author(s):  
Li Tian ◽  
Dai Xiaoxia ◽  
Zhang Chengwei

We propose two algorithms for elliptic boundary value problems in shape optimization. With the finite element method, the optimization problem is replaced by a discrete variational problem. We give rules and use them to decide which elements are to be reserved. Those rules are determined by the optimization; as a result, we get the optimal design in shape. Numerical examples are provided to show the effectiveness of our algorithms.


2011 ◽  
Vol 261-263 ◽  
pp. 1694-1698 ◽  
Author(s):  
Feng Yi Tan ◽  
Xin Zhi Wang

The bearing performance of composite foundation improved by flexible piles was influenced by changes of cushion’s modulus, the modulus ratio between soil on bottom of pile and soil surrounded pile, which was analyzed by the finite element method. Results showed that: 1.For single pile, by increasing of cushion’s modulus, the bearing performance nearby the top of flexible pile increased apparently, and the common tendency of settlement of pile and soil surrounded piles was affected negatively. For multi-piles, the increasing of cushion’s modulus resulted in the increasing of bearing performance and the common tendency of settlement of piles and soil surrounded piles was affected positively. 2.The change of modulus ratio between soil surrounded piles and soil on bottom of piles resulted positively in the change of frictional resistance and end-bearing performance nearby the bottom of single pile and reduced the settlement of composite foundation. But the multi-pile borne absolutely all loading due to the increasing of modulus ratio, and both of piles and soil surrounded piles had the same tendency of settlement.


Wood Research ◽  
2021 ◽  
Vol 66 (2) ◽  
pp. 321-330
Author(s):  
Tianxing Zhang ◽  
Wengang Hu

The effect of tenon length and tenon width on withdrawal load capacity of mortise and tenon (M-T) joint was studied based on the finite element method (FEM), and the relationship of withdrawal load capacity relating to tenon length and tenon width was regressed using response surface method. The results showed that the tenon length and tenon width had remarkable effects on withdrawal load capacity of M-T joint T-shaped sample. The effect of tenon length on withdrawal load capacity was greater than tenon width. The regression equation used to predict the withdrawal load capacity was capable of optimizing the tenon sizes of M-T joint with R-square of 0.926. Using FEM can get more knowledge of M-T joint visually, and reduce the costs of materials and time of experiments.


Author(s):  
Anh Tuan Nguyen ◽  
Van Dung Tran

The paper aims to investigate the relationship between factors which have the impacts on the tunnel and the ground and establish formulas to calculate the correlation of the passive failure pressure in front of tunnel face in the vertical and horizontal directions by using the Finite Element Method (FEM).


2011 ◽  
Vol 337 ◽  
pp. 236-241 ◽  
Author(s):  
Xin Hua Huang ◽  
Hua Xiang ◽  
Xin Cun Zhuang ◽  
Zhen Zhao

Nowadays, the compound fine-blanking forming process is one of the most important processes to produce complicate multifunctional parts without subsequent machining. However, the big die-roll occurs in the sharp area is a common problem in this process. In this paper, the method with negative punch-die clearance was proposed to solve this problem by comparing three feasible plans. In addition, the influence on the process with different value of the negative punch-die clearance was studied by the finite element method (FEM). The results of this study verified that the process with suitable value of the negative punch-die clearance can result in significant decrease of the die-roll size. The relationship between the material flow near the region of die-roll and the punch-die clearance was also clarified.


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