Using Simulation to Help Specify Design Parameters for Vacuum-Assisted Needle Biopsy Systems

2018 ◽  
Vol 13 (1) ◽  
Author(s):  
Xuelian Gu ◽  
Fangqiu Hu ◽  
Chi-Lun Lin ◽  
Arthur Erdman ◽  
Licheng Lu
Keyword(s):  
Needle Biopsy ◽  
Reaction Force ◽  
Peak Stress ◽  
Axial Direction ◽  
Tissue Reaction ◽  
Design Parameters ◽  
Stress And Strain ◽  
Medical Procedure ◽  
Element Analysis ◽  
The Finite Element Analysis

Needle biopsy is a routine medical procedure for examining tissue or biofluids for the presence of disease using standard methods of pathology. The finite element analysis (FEA) methodology can provide guidance for optimizing the geometric parameters. The needle biopsy is simulated and analyzed while varying the needle angle, the aperture size and the slice-push ratio k. The results indicate that tissue reaction force in the axial direction of needle gradually decreases, and the stress and strain are more concentrated at the tip of needle with the increases of tip angle; the tissue reaction force decreases, and the torque increases while the slice-push ratio increases; and higher slice–push ratio can increase the peak stress concentration on the cutting edge and deformation of tissue; in the process of core needle cutting, increasing slice–push ratio can reduce the tissue reaction force significantly. While the aperture on distal wall of outer cannula becomes wider, the tissue reaction force increases significantly, and the cutting process will be more unstable. The results have the potential to provide important insight for improving the needle biopsy design process.

Optimal Design of Bi- and Multi-Stable Compliant Cellular Structures

2018 ◽  
Author(s):  
Quantian Luo ◽  
Liyong Tong
Keyword(s):  
Optimal Design ◽  
Virtual Work ◽  
Reaction Force ◽  
Nonlinear Finite Element ◽  
Cellular Structures ◽  
Stress And Strain ◽  
Principle Of Virtual Work ◽  
Stable States ◽  
Threshold Method ◽  
Element Analysis

This paper presents optimal design for nonlinear compliant cellular structures with bi- and multi-stable states via topology optimization. Based on the principle of virtual work, formulations for displacements and forces are derived and expressed in terms of stress and strain in all load steps in nonlinear finite element analysis. Optimization for compliant structures with bi-stable states is then formulated as: 1) to maximize the displacement under specified force larger than its critical one; and 2) to minimize the reaction force for the prescribed displacement larger than its critical one. Algorithms are developed using the present formulations and the moving iso-surface threshold method. Optimal design for a unit cell with bi-stable states is studied first, and then designs of multi-stable compliant cellular structures are discussed.

Finite Element Analysis and Optimization of the Truss of Installing Wave-Maker Based on ANSYS

2013 ◽  
Vol 313-314 ◽  
pp. 1038-1041
Author(s):  
Shou Jun Wang ◽  
Xing Xiong ◽  
Chao Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Design Parameters ◽  
Analysis Software ◽  
Element Analysis ◽  
Large Span ◽  
The Finite Element Analysis ◽  
Wave Maker

According to uncertainty of the design parameters for large span truss of installing wave-maker, in order to avoid the waste of materials,the truss is analyzed based on the finite element analysis software ANSYS to find out its weaknesses and various parts of the deformation. On the premise of ensuring the intensity and stiffness, the weight of the truss is reduced by adjusting its sizes and selecting different profiles, so as to achieve the optimization of the truss of installing wave-maker.

Finite Element Analysis on Rack and Pinion of Roadheader

2013 ◽  
Vol 791-793 ◽  
pp. 718-721
Author(s):  
Man Man Xu ◽  
Yu Li ◽  
Sai Nan Xie ◽  
Qing Hua Chen
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Spur Gear ◽  
Stress And Strain ◽  
Analysis Method ◽  
Element Analysis ◽  
The Road ◽  
The Finite Element Analysis ◽  
Gear Rack ◽  
Stress And Strain Distribution

To analyse the road-header rack and pinion by using the finite element analysis software COSMOS/WORKS. Compared to the traditional analytic calculation and numerical analysis method, it is more intuitively get 28 ° pressure angle spur gear rack meshing stress and strain distribution, which can rack and pinion improvements designed to provide scientific reference.

scholarly journals Optimization of Design Parameters of Spiral Spring for Active Headrest Deployment

2018 ◽  
Vol 167 ◽  
pp. 02017
Author(s):  
Yunsik Yang ◽  
Euy Sik Jeon ◽  
Dae Ho Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Optimal Design ◽  
Relative Motion ◽  
Design Parameter ◽  
Development Time ◽  
Design Parameters ◽  
Element Analysis ◽  
Spiral Spring ◽  
The Finite Element Analysis

Several studies have been conducted to prevent neck injury in rear-end collision. The headrest of the seat which suppresses the relative motion of the head and the torso can suppress the extension of the head, thereby alleviating the injury. The active headrest has a mechanism that supports the head by deploying the headrest at the rear-end collision. The spring remains compressed or twisted until a collision signal is generated and the headrest is deployed after the collision signal. Depending on the shape and deployment structure of the spring, a spring design with a high resilience that is acceptable to the headrest is required. In this paper, design parameter of spiral spring suitable for the structure of the developed headrest is selected, prototypes are fabricated, and development parameters such as development time and development distance are checked and optimal design parameters of the spiral spring are derived. The feasibility of the headrest with the designed spiral spring was verified by the finite element analysis.

Two-Step Approach of Stress Classification and Primary Structure Method

1999 ◽  
Vol 122 (1) ◽  
pp. 2-8 ◽  
Author(s):  
Ming-Wan Lu ◽  
Yong Chen ◽  
Jian-Guo Li
Keyword(s):  
Primary Structure ◽  
Peak Stress ◽  
Classification Problem ◽  
Linearization Method ◽  
Equivalent Linearization ◽  
Element Analysis ◽  
Primary Stress ◽  
Stress Classification ◽  
The Finite Element Analysis ◽  
Asme Code

A key problem in engineering applications of “design by analysis” approach is how to decompose a total stress field obtained by the finite element analysis into different stress categories defined in the ASME Code III and VIII-2. In this paper, we suggest a two-step approach (TSA) of stress classification and a primary structure method (PSM) for identification of primary stress. Together with the equivalent linearization method (ELM), the stress classification problem is well solved. Some important concepts and ideas discussed by Lu and Li [Lu, M. W., and Li, J. G., 1986, ASME PVP-Vol. 109, pp. 33–37; Lu, M. W., and Li, J. G., 1996, ASME PVP-Vol. 340, pp. 357–363] are introduced. They are self-limiting stress, multi-possibility of stress decomposition, classification of constraints, and primary structures. For identification of peak stress, a modified statement of its characteristic and a “1/4 thickness criterion” are given. [S0094-9930(00)00201-8]

Large Deformation Modeling Applied to the Sheet Metal Electromagnetic Forming

2008 ◽  
Author(s):  
C. Dumitras ◽  
I. Cozminca
Keyword(s):  
Finite Element ◽  
Deformation Process ◽  
Electromagnetic Forming ◽  
Stress And Strain ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Strain Fields ◽  
The Finite Element Analysis ◽  
History Of ◽  
Free Bulging

The electromagnetic forming has the advantage of a minimum forming time, but this is a major obstacle in determining the process’s history of the forming workpiece. Both experimental and theoretical known analysis methods for this process give a discret array of data (only for the displacements). One considers it is more adequate to use the finite element method in studying this process. The main advantage of the finite element analysis is given by the fact that it shows the stress and strain fields in a continuous way during the deformation process. Also, it offers a model from which one can predict the final shape of the part and the possible crack zones. One present a compared study of the experimental and the simulated results achieved of the free bulging aluminum specimens by electromagnetic impulses.

Development of a Belt Conveyor Cooling System for Concrete Aggregates

2011 ◽  
Author(s):  
Khaled I. E. Ahmed ◽  
A. M. S. Hamouda ◽  
M. S. Gadala
Keyword(s):  
Finite Element ◽  
Cooling System ◽  
Initial Conditions ◽  
Element Model ◽  
Design Parameters ◽  
Element Analysis ◽  
Conveyor System ◽  
Concrete Aggregates ◽  
Concrete Production ◽  
The Finite Element Analysis

Using hot aggregates, in concrete production, results in a drop in compressive strength of the produced concrete. Various methods have been proposed for cooling concrete aggregates. This paper proposes a new design for a conveyor system for cooling the aggregates during hot seasons. Simulation of the heat flow during the cooling process over the conveyor is analyzed with the objective of understanding the effect of the various design parameters and achieving minimum cooling time with the least possible power. A finite element model for the new design is proposed and discussed. Challenges facing numerical simulation are addressed in this paper. The results of the finite element analysis of the new design are presented for various initial conditions and cooling rates.

Non-Invasive Test of Soft Tissue for Tissue Reaction in Needle Biopsy

2011 ◽  
Vol 66-68 ◽  
pp. 983-988
Author(s):  
M. Liu ◽  
Q.H. Zhang ◽  
L.Y. Gao ◽  
Xue Mei Qin
Keyword(s):  
Finite Element ◽  
Soft Tissue ◽  
Finite Element Model ◽  
Needle Biopsy ◽  
Element Model ◽  
Tissue Reaction ◽  
Medical Procedure ◽  
Non Invasive ◽  
Invasive Test ◽  
Force Time

Needle biopsy is a widely used medical procedure in which a tissue sample is cut and removed by needle for examination to identify and diagnose cancer and other diseases. Predictions of soft tissue deformation and reaction caused by needle insertion are important for the accuracy of this procedure. In this paper, in order to aquire the properties of soft tissue, indentation experiments of porcine livers are performed as non-invasive test to measure the force response depending on time in various indentation depth and indentation velocities conditions. A nonlinear least square method on Matlab have been created to fit the indentation results. According to the experimental and fitting indentation force-time curves, the coefficients of Neo-Hookean model and Kelvin model which are selected to develop the nonlinear model of porcine liver are acquired . Finally, a finite element model of liver based on experimental data is finally developed and succeeds in simulating the stress relaxation character and force-time curve. This finite element model and methodology can be used to investigate soft tissue reaction in needle biopsy.

Optimization Design of Hydraulic Cylinder Based on ANSYS

2012 ◽  
Vol 562-564 ◽  
pp. 709-712
Author(s):  
Yi Lun Han ◽  
Li Jun Huang ◽  
Xue Lei Wen
Keyword(s):  
Optimization Design ◽  
Three Dimensional ◽  
Basic Structure ◽  
Hydraulic Cylinder ◽  
Stress And Strain ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
The Cost

The basic structure of the piston hydraulic cylinder was introduced. A three-dimensional model was carried out for the hydraulic cylinder by using Pro/E soft，the finite element analysis to the largest hydraulic condition while hydraulic cylinder working by using ANSYS soft，and the distribution of the stress and strain of hydraulic cylinder was derived from it. It optimized the structure of hydraulic cylinder effectively and the cost was saved.

Optimum design of a cutting tool for manufacturing rotary knives

2008 ◽  
Vol 223 (2) ◽  
pp. 463-472 ◽  
Author(s):  
S-L Chang ◽  
H-C Tseng ◽  
J-K Hsieh ◽  
J-H Liu ◽  
C-H Hung
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Sequential Quadratic Programming ◽  
Traditional Method ◽  
Cutting Tool ◽  
Design Parameters ◽  
Element Analysis ◽  
Manufacturing Efficiency ◽  
The Finite Element Analysis ◽  
Chip Discharge

In this article, the design parameters of a cutting tool for manufacturing a rotary knife with multi-cutting angles have been studied. An objective function and constraints are defined, and optimized solutions are found by using two methods: global search and sequential quadratic programming. Hobbing and the concept of tooth undercutting were used to manufacture a rotary knife with multi-cutting angles. The proposed method not only improved the manufacturing efficiency over the traditional method (milling and grinding), but also significantly improved the strength of the rotary knife and the chip discharge ability, as shown by the finite-element analysis of the stress distribution and deformation of two different kinds of rotary knives.

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