Finite-element simulation of the photoacoustic–thermal signal generation

1986 ◽  
Vol 64 (9) ◽  
pp. 1030-1036 ◽  
Author(s):  
D. Lévesque ◽  
G. Rousset ◽  
L. Bertrand

The ability to use the finite-element method to solve numerically the frequency-dependent coupled equations of the photoacoustic–thermal effect is demonstrated. Both solids and fluids are simulated by the same set of equations with temperature and displacement as variables. The main interest of this formulation lies in its great flexibility to deal with mixed fluid–solid systems. As a first application, we consider the influence of thermoacoustic coupling on the pressure in a photoacoustic cell. We show that with increasing frequency, a transition from an isothermal to an adiabatic process occurs. Subsequently, results obtained from a numerical simulation of the photoacoustic cell, which includes the effect of a residual volume, are in good agreement with existing experimental data.

2018 ◽  
Vol 178 ◽  
pp. 02010 ◽  
Author(s):  
Dorin Luca

Extrusion is the plastic deformation process that allows for the highest degree of complexity profiles to be obtained. This paper presents the simulation of a cold forward extrusion process using the finite element method. The results obtained show the stresses, strains and temperatures during the plastic deformation of the material, as well as the stresses and strains in the punch and die. The analysis of the results obtained for different geometric dimensions of the working tools allowed the optimization of the studied extrusion process. In order to validate the finite element model, experiments were carried out with the data acquisition from the real process, which allowed the appreciation that numerical and experimental data are found in a good agreement.


2010 ◽  
Vol 97-101 ◽  
pp. 2951-2954
Author(s):  
Yong Yang ◽  
Hui Hui Li ◽  
Guang Yao Meng

A physics-based material processing simulation is approached to research the machining distortion for titanium alloy aircraft monolithic component by the finite element method (FEM). Several key technologies, such as material constitutive model, material removal methodology of machining process, determination and application of cutting loads, have been implemented to improve the accuracy of finite element simulation. To verify the FEM result, an experiment is carried out. The distortion position and dimension of aircraft monolithic component resulting from FEM show a good agreement with the experiment result, which indicates that the key technologies presented in the paper are practicable and can be used to simulate the machining process of monolithic component to predict its distortion.


Author(s):  
S. G. Qu ◽  
W. J. Deng

This work is focused on the development of a numerical model with the help of the finite element method to predict the magnitude and distribution of deformation associated with the self-piercing riveting process. A 2D axisymmetric model of the self-piercing riveting process is presented using the commercial implicit finite element code MSC.Superform. The flow stress of the work-material is taken as a function of strain, strain-rate and temperature. The shape of the rivet joint and the stress, strain and damage in both of the rivet and workpiece sheets are determined. The information obtained from the process simulation, such as force, metal flow and details of die fill are discussed. The calculated punching forces and the shape of the rivet joint are compared with experimental data and found to be in good agreement. Defects in the riveting are analyzed and are categorized into penetration, necking and lap formation. The effects of workpiece temperature on punching force were also discussed.


1992 ◽  
Vol 20 (4) ◽  
pp. 230-253 ◽  
Author(s):  
T. Akasaka ◽  
K. Kabe ◽  
M. Koishi ◽  
M. Kuwashima

Abstract The deformation behavior of a tire in contact with the roadway is complicated, in particular, under the traction and braking conditions. A tread rubber block in contact with the road undergoes compression and shearing forces. These forces may cause the loss of contact at the edges of the block. Theoretical analysis based on the energy method is presented on the contact deformation of a tread rubber block subjected to compressive and shearing forces. Experimental work and numerical calculation by means of the finite element method are conducted to verify the predicted results. Good agreement is obtained among these analytical, numerical, and experimental results.


2007 ◽  
Vol 340-341 ◽  
pp. 353-358 ◽  
Author(s):  
M. Loh-Mousavi ◽  
Kenichiro Mori ◽  
K. Hayashi ◽  
Seijiro Maki ◽  
M. Bakhshi

The effect of oscillation of internal pressure on the formability and shape accuracy of the products in a pulsating hydroforming process of T-shaped parts was examined by finite element simulation. The local thinning was prevented by oscillating the internal pressure. The filling ratio of the die cavity and the symmetrical degree of the filling was increased by the oscillation of pressure. The calculated deforming shape and the wall thickness are in good agreement with the experimental ones. It was found that pulsating hydroforming is useful in improving the formability and shape accuracy in the T-shape hydroforming operation.


2017 ◽  
Vol 54 (1) ◽  
pp. 180-179 ◽  
Author(s):  
Raul Cormos ◽  
Horia Petrescu ◽  
Anton Hadar ◽  
Gorge Mihail Adir ◽  
Horia Gheorghiu

The main purpose of this paper is the study the behavior of four multilayered composite material configurations subjected to different levels of low velocity impacts, in the linear elastc domain of the materials, using experimental testing and finite element simulation. The experimental results obtained after testing, are used to validate the finite element models of the four composite multilayered honeycomb structures, which makes possible the study, using only the finite element method, of these composite materials for a give application.


2008 ◽  
Vol 22 (31n32) ◽  
pp. 6218-6223 ◽  
Author(s):  
W. HOU ◽  
Z. WANG ◽  
L. ZHAO ◽  
G. LU ◽  
D. SHU

This paper is concerned with the load-carrying capacities of a circular sandwich panel with metallic foam core subjected to quasi-static pressure loading. The analysis is performed with a newly developed yield criterion for the sandwich cross section. The large deflection response is estimated by assuming a velocity field, which is defined based on the initial velocity field and the boundary condition. A finite element simulation has been performed to validate the analytical solution for the simply supported cases. Good agreement is found between the theoretical and finite element predictions for the load-deflection response.


2008 ◽  
Vol 367 ◽  
pp. 193-200
Author(s):  
Branko Grizelj ◽  
M. Plancak ◽  
Branimir Barisic

The paper analyses the process of simulation forward-backward extrusion. In metal forming industries, many products have to be formed in large numbers and with highly accurate dimensions. To save energy and material it is necessary to understand the behavior of material and to know the intermediate shapes of the formed parts and the mutual effects between tool and formed party during the forming process. These are normally based on numerical methods which take into account all physical conditions of the deformed material during the process. For this purpose, the finite element method has been developed in the past in different ways. The paper highlights the finite element simulation as a very useful technique in studying, where there is a generally close correlation in the load results obtained with finite elements method and those obtained experimentally.


Author(s):  
Vikas Radhakrishna Deulgaonkar ◽  
S.N. Belsare ◽  
Naik Shreyas ◽  
Dixit Pratik ◽  
Kulkarni Pranav ◽  
...  

Present work deals with evaluation of stress, deflection and dynamic properties of the folded vehicle structure. The folded vehicle in present case is a single seat vehicle intended to carry one person. Design constraints are the folded dimensions of the vehicle and the maximum vehicle speed is limited to 15m/s. Using classical calculations dimensions of the vehicle are devised. Different materials are used for seat, telescopic support and chassis of the foldable vehicle. computer aided model is prepared using CATIA software. Finite element analysis of the foldable vehicle has been carried out to evaluate the static and dynamic stresses induced in the vehicle components. Meshing of the foldable vehicle is carried using Ansys Workbench. From modal analysis six mode shapes of the foldable vehicle are formulated, corresponding frequencies and deflections are devised. Mesh generator is used to mesh the foldable vehicle. The deflection and frequency magnitudes of foldable vehicle evaluated are in good agreement with the experimental results available in literature for similar materials.


1975 ◽  
Vol 10 (3) ◽  
pp. 167-171 ◽  
Author(s):  
F Ginesu ◽  
B Picasso ◽  
P Priolo

Results on the plastic collapse behaviour of an axisymmetric rotating shell, obtained by Limit Analysis and the Finite Element Method, are in good agreement with experimental data. The Finite Element Method, though computationally rather costly, permits, however, a more complete analysis of elasto-plastic behaviour. For the present case, the Limit Analysis has the advantage of greater computational simplicity and leads to a quite satisfactory forecast of collapse speed from the engineering point of view.


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