scholarly journals Breast Tumor Simulation and Parameters Estimation Using Evolutionary Algorithms

2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
Manu Mital ◽  
Ramana M. Pidaparti
Keyword(s):  
Finite Element ◽  
Evolutionary Algorithms ◽  
Surface Temperature ◽  
Temperature Profile ◽  
Heat Generation ◽  
Breast Tumor ◽  
Fitness Function ◽  
Parameters Estimation ◽  
Finite Element Software ◽  
The Relationship

An estimation methodology is presented to determine the breast tumor parameters using the surface temperature profile that may be obtained by infrared thermography. The estimation methodology involves evolutionary algorithms using artificial neural network (ANN) and genetic algorithm (GA). The ANN is used to map the relationship of tumor parameters (depth, size, and heat generation) to the temperature profile over the idealized breast model. The relationship obtained from ANN is compared to that obtained by finite element software. Results from ANN training/testing were in good agreement with those obtained from finite element model. After ANN validation, GA is used to estimate tumor parameters by minimizing a fitness function involving comparing the temperature profiles from simulated or clinical data to those obtained by ANN. Results show that it is possible to determine the depth, diameter, and heat generation rate from the surface temperature data (with 5% random noise) with good accuracy for the 2D model. With 10% noise, the accuracy of estimation deteriorates for deep-seated tumors with low heat generation. In order to further develop this methodology for use in a clinical scenario, several aspects such as 3D breast geometry and the effects of nonuniform cooling should be considered in future investigations.

Optimization Analysis for Radial Support by Finite Elements Method

2012 ◽  
Vol 466-467 ◽  
pp. 734-738
Author(s):  
Cheng Ming Li ◽  
Yi Fan Wang
Keyword(s):  
Finite Element ◽  
Finite Elements ◽  
Optimal Solution ◽  
Support Point ◽  
Mirror Surface ◽  
Optimization Analysis ◽  
Primary Mirror ◽  
Finite Element Software ◽  
The Relationship ◽  
Surface Figure

Primary mirror’ surface figure is affected by supporting structure obviously. Especially for large-aperture telescope, the surface figure is significant because of primary mirror’ self-weight. For the requirement of the usage, it’s necessary to minimize the surface figure from self-weight by reasonable supporting scheme. The text optimized support point and force of radial support to minimize the surface figure by finite-element software. At the same time, it studied the relationship between support point and counterweight to reduce the weight of support structure. At last, it gave the optimal solution.

Experimental Investigations and Finite-Element Modeling of Thermoplastic Effect during Tensile Tests of Metal Material

2013 ◽  
Vol 634-638 ◽  
pp. 2835-2838
Author(s):  
Wei Qing Wang ◽  
Li Yang ◽  
Shi Gui Lv
Keyword(s):  
Plastic Deformation ◽  
Finite Element ◽  
Temperature Field ◽  
Surface Temperature ◽  
Strain Rate ◽  
Numerical Procedure ◽  
Infrared Camera ◽  
Tensile Tests ◽  
Experimental Investigations ◽  
Finite Element Software

During plastic deformation of materials, part of the plastic work is converted into heat, and the temperature field will be changed, this phenomenon is well known as thermoplastic effect. Based on the analysis of thermoplastic effect, the surface temperature of Q235 steel during quasi-static tensile tests was measured by using an infrared camera, and the surface temperature field and it versus time for different strain rate were obtained. A numerical procedure was devised to model the thermoplastic effect during the tensile tests by using ANSYS software. The results showed that, the heat loss during deformation process will be smaller as the strain rate increase, and the temperature increase on the specimen surface generated by the plastic deformation will be higher. The simulation results matched well with the experiment results showed that it was a good way to analyse the thermoplastic effect by the commercial finite element software.

The Calculation of Deformation Force in Closed Muti-Ram Forging

2010 ◽  
Vol 154-155 ◽  
pp. 969-972
Author(s):  
Chun Dong Zhu ◽  
Bo Zhou ◽  
Hui Wang
Keyword(s):  
Finite Element ◽  
Principal Stress ◽  
Rigid Plastic ◽  
Finite Element Software ◽  
Deformation Force ◽  
The Relationship ◽  
Complex Parts

With the example of rod, this paper introduces principal stress method in the analysis and calculation of deformation force in complex parts manufactured by closed multi-ram forging. The relationship between deformation force and stroke is simulated by rigid-plastic finite element software, and then verified by experiment .It has been shown that principal stress method are accurate in calculating the deformation force of multi-ram forging by comparing and analyzing the results of these three ways.

The Relationship between Deflection and Maximum Stress Distributed on the Layer Bottom in the Typical Semi-Rigid Bituminous Pavement Structure

2011 ◽  
Vol 97-98 ◽  
pp. 85-90 ◽  
Author(s):  
Zhi Zhong Zhao ◽  
Kui Li ◽  
Ning Zhang
Keyword(s):  
Finite Element ◽  
Maximum Stress ◽  
Structure Design ◽  
Construction Control ◽  
The Road ◽  
Finite Element Software ◽  
Pavement Structure ◽  
The Relationship ◽  
Highway Pavement

This article carries on the test to materials of the roadbed and the pavement in the room, and obtains mechanics computation parameter; Considered the road overload situation, we carries on the modeling computation to the typical semi-rigid bituminous pavement structure through using the finite element software; Carrying on the analysis, we obtains the correlation formula between the road deflection and various structures level maximum stress .it can provide the theory basis and the instruction experience for the highway pavement structure design, the examination and the construction control.

scholarly journals Numerical Investigation of Tool Parameters Influence on the Interlock Forming During Flat Clinching Process

2021 ◽  
Author(s):  
Zhiyong Wang ◽  
Shanling Han ◽  
Zhiyong Li ◽  
Yong Li
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Linear Relationship ◽  
Numerical Investigation ◽  
Vital Role ◽  
Blank Holder ◽  
Finite Element Software ◽  
Punch Radius ◽  
Deform 2D ◽  
The Relationship

Abstract Tool parameters play a vital role in the mechanical interlock formation during the flat clinching process, to understand the influence of tool parameters on the interlock formation, the finite element software DEFORM-2D was used to build the numerical model of the flat clinching process, and the numerical model was verified by the experiment. The influences of the punch radius, punch fillet radius, and blank holder radius on the interlock formation of the clinched joint were investigated using the numerical model. Then, the relationship between the punch radius and blank holder radius was studied. The results showed that the interlock gradually increases with the increase of the blank holder radius, after that, the interlock begins to decrease. To maximize the interlock, the punch radius and the blank holder radius should be increased simultaneously. It can be concluded that the blank holder radius and the punch radius should keep in a linear relationship when designing the geometric dimensions of the flat clinch tools, which can promote the application of flat clinching process in car body manufacturing.

Collapse of Sharp-Notched 6061-T6 Aluminum Alloy Tubes Under Cyclic Bending

2016 ◽  
Vol 16 (07) ◽  
pp. 1550035 ◽  
Author(s):  
Chen-Cheng Chung ◽  
Kuo-Long Lee ◽  
Wen-Fung Pan
Keyword(s):  
Finite Element ◽  
Aluminum Alloy ◽  
Cyclic Bending ◽  
Finite Element Software ◽  
Buckling Failure ◽  
Simulation Results ◽  
Number Of Cycles ◽  
The Moment ◽  
The Relationship ◽  
Good Agreement

The mechanical behavior and buckling failure of sharp-notched 6061-T6 aluminum alloy tubes with different notch depths subjected to cyclic bending are experimentally and theoretically investigated. The experimental moment–curvature relationship exhibits an almost steady loop from the beginning of the first cycle. However, the ovalization–curvature relationship exhibits a symmetrical, increasing, and ratcheting behavior as the number of cycles increases. The six groups of tubes tested have different notch depths, from which two different trends can be observed from the relationship between the controlled curvature and the number of cycles required to ignite buckling. Finite element software ANSYS is used to simulate the moment–curvature and ovalization–curvature relationships. Additionally, a theoretical model is proposed for simulation of the controlled curvature-number of cycles concerning the initiation of buckling. Simulation results are compared with experimental test data, which shows generally good agreement.

Numerical Analysis of the GF/UHMWPEF Interply Hybrid NOL Ring Critical Volume Fraction

2012 ◽  
Vol 457-458 ◽  
pp. 449-452
Author(s):  
Ming Lin Xu ◽  
Xiao Qing Wu ◽  
Ming Kang An
Keyword(s):  
Finite Element ◽  
Volume Fraction ◽  
Critical Volume ◽  
Tooth Contact Analysis ◽  
Breaking Strain ◽  
Finite Element Software ◽  
Critical Volume Fraction ◽  
The Matrix ◽  
The Relationship ◽  
Strain Model

The tensile test of NOL ring composites with different interply hybrid ratio is simulated by finite element software. The relationship between the stress of Naval Ordnance Laboratory(NOL) ring and the volume fraction of UHMWPEF is linear when the matrix suffering from the equal loading, but tower suddenly appears at the point of 56.25% which is about the critical volume fraction. The critical volume fraction of hybrid NOL ring is figured out on the basis of the constant strain model. By contrast, the results of the Finite Element Method (FEM) and constant strain model have subtle differences. Tooth contact analysis can exactly predict the stress of the interply hybrid NOL ring and the critical volume fraction of GF in interply hybrid NOL ring which has lower breaking strain than UHMWPEF does.

scholarly journals Spaghetti Breaking Dynamics

2021 ◽  
Author(s):  
Yi Zhang ◽  
Xiang Li ◽  
Yuanfan Dai ◽  
Bohua Sun
Keyword(s):  
Finite Element ◽  
Dimensional Analysis ◽  
Length Ratio ◽  
Elastic Rod ◽  
Finite Element Software ◽  
Fracture Dynamics ◽  
Simulation Results ◽  
Scientific Judgment ◽  
The Relationship ◽  
Rod Fracture

Why are pieces of spaghetti generally broken into three to ten segments instead of two as one thinks? How can one obtain the desired number of fracture segments? For these problems, in this paper a strand of spaghetti is considered an elastic rod, and the finite-element software ABAQUS is used to simulate the detailed fracture dynamics of the elastic rod. By changing the size (length and diameter) of the rod, the relevant data on the fracture limit curvature and the number of fractured segments of the elastic rod are obtained. The ABAQUS simulation results confirm the scientific judgment of B. Audoly and S. Neukirch (Fragmentation of rods by cascading cracks: Why spaghetti does not break in half. Phys Rev Lett 95: 095505). Using dimensional analysis to fit the finite-element data, two relations of the elastic rod fracture dynamics are obtained: (1) the relationship between the fracture limit curvature and the diameter, and (2) the relationship between the number of fracture segments and the diameter-length ratio. Results reveal that when the length is constant, the larger the diameter (the smaller the diameter-length ratio D/L), the smaller the limit curvature; and the larger the diameter-length ratio D/L, the fewer the number of fractured segments. The relevant formulations can be used to obtain the desired number of broken segments of spaghetti by changing the diameter-to-length ratio.

Piezoelectric Properties of 1-3 Piezoelectric Tubular Composites

2012 ◽  
Vol 217-219 ◽  
pp. 24-30 ◽  
Author(s):  
Yu Ting Ma ◽  
Jun Zhong ◽  
Li Zhang ◽  
Yun Liang Wu
Keyword(s):  
Finite Element ◽  
Aspect Ratio ◽  
Electric Field Distribution ◽  
Piezoelectric Properties ◽  
Volume Fraction ◽  
Uniform Electric Field ◽  
Finite Element Software ◽  
The Relationship ◽  
Tube Density ◽  
Theoretical Results

The piezoelectric coefficients of 1-3 piezoelectric tubular composites are studied. Taking into account the non-uniform electric field distribution in piezoelectric tube, the piezoelectric coefficients as functions of volume fraction, aspect ratio, tube density and matrix materials were discussed. By means of finite element software, the relationship between piezoelectric coefficients and ceramic volume fraction was derived to validate theoretical results. This research provides theoretical guidance and basis for the design of 1-3 piezoelectric tubular composites.

Nonlinear Finite Elements Analysis on Structure of Pumping Station in the Joint Hub of Sluice and Pumping Station

2011 ◽  
Vol 90-93 ◽  
pp. 2546-2552 ◽  
Author(s):  
Qiu Lin Cao ◽  
Yikai Meng ◽  
Lei Chen
Keyword(s):  
Finite Element ◽  
Finite Elements ◽  
Finite Elements Analysis ◽  
Pumping Station ◽  
Finite Element Software ◽  
Side Load ◽  
Nonlinear Finite Elements ◽  
The Relationship

Aiming at the pivotal project is decorated jointly by sluice and pumping station, thus the relationship between each other is more complex. By using 3-D finite element software ABAQUS, the structure of pumping station was studied. Two methods were used when modeling and analyzing. For the method 1, only the model of pumping station was built and the check sluice was taken as a side load when calculating. For the method 2, the whole model of the joint hub of sluice and pumping station was built. The displacements and strength of the structure of pumping station can meet the requirements according to the calculated results. There is little difference between the calculated results of the two kinds of methods by comparison, but for the method 1, the calculations about displacements are all unsafe and it should be given enough attention, thereby the reliability and security of the design of similar projects will be guaranteed.

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