Finite Element Analysis of Contact Force Models During Solid Elastic and Plastic Bodies Impact

Author(s):  
Gustavo Simão Rodrigues ◽  
Hans Ingo Weber ◽  
Larissa Driemeier

There are many models of impact used to predict the post-impact conditions of a system and all of them are based on Hertz’s theory, dated from the nineteenth century, where the repulsive force is proportional to the deformation of the bodies under contact and may also be proportional to the rate of deformation. The objective of this work is to analyze the behavior of the bodies during impact using some contact models and compare the results to a Finite Element Method model. The main parameters which will be evaluated are the body velocities, the contact force and the deformation of the bodies. An advantage of using the Finite Element Method is the possibility to apply plastic deformation to the model according to material definition. In the present study, it will be used Johnson–Cook plasticity model where the parameters are obtained based on empirical tests of real materials. Thus, it is possible to compare the behavior of elastic and plastic numerical models with the finite element model and to verify how these models reproduce the impact between solid bodies.

Author(s):  
J. Poirier ◽  
P. Radziszewski

The natural frequencies of circular saws limit the operating speeds of the saws. Current industry methods of increasing natural frequency include pretensioning, where plastic deformation is induced into the saw. To better model the saw, the finite element model is compared to current software for steel saws; C-SAW, a software program that calculates frequencies for stiffened circular saws. Using C-SAW and the finite element method the results are compared and the finite element method is validated for steel saws.


2013 ◽  
Vol 683 ◽  
pp. 556-559
Author(s):  
Bin Bin Jiao ◽  
Fu Sheng Yu ◽  
Yun Jiang Li ◽  
Rong Lu Zhang ◽  
Gui Lin Du ◽  
...  

In order to study the distribution of the stress field in the high-speed intermittent cutting process, finite element model of high-speed intermittent cutting is established. Exponential material model of the constitutive equation and adaptive grid technology are applied in the finite element analysis software AdvantEdge. The material processing is simulated under certain cutting conditions with FEM ( Finite Element Method ) and the distribution of cutting force, stress field, and temperature field are received. A periodic variation to the cutting force and temperature is showed in the simulation of high-speed intermittent cutting. Highest value of the milling temperature appears in front contacting area of the knife -the chip.and maximum stress occurs at the tip of tool or the vicinity of the main cutting edge. The analysis of stress and strain fields in-depth is of great significance to improve tool design and durability of tool.


2008 ◽  
Vol 575-578 ◽  
pp. 1139-1144 ◽  
Author(s):  
Chan Chin Wang

A simulator based on rigid-plastic finite element method is developed for simulating the plastic flow of material in forging processes. In the forging process likes backward extrusion, a workpiece normally undergoes large deformation around the tool corners that causes severe distortion of elements in finite element analysis. Since the distorted elements may induce instability of numerical calculation and divergence of nonlinear solution in finite element analysis, a computational technique of using the Euler’s fixed meshing method is proposed to deal with large deformation problem by replacing the conventional way of applying complicated remeshing schemes when using the Lagrange’s elements. With this method, the initial elements are generated to fix into a specified analytical region with particles implanted as markers to form the body of a workpiece. The particles are allowed to flow between the elements after each deformation step to show the deforming pattern of material. The proposed method is found to be effective in simulating complicated material flow inside die cavity which has many sharp edges, and also the extrusion of relatively slender parts like fins. In this paper, the formulation of rigid-plastic finite element method based on plasticity theory for slightly compressible material is introduced, and the advantages of the proposed method as compared to conventional one are discussed.


2021 ◽  
Vol 50 (02) ◽  
Author(s):  
NGOC THAI HUYNH ◽  
CONG RO HOANG ◽  
TRUNG KIEN TRAN ◽  
VAN HOAI LE

The investigation analyzes effects of clearance size in revolute and spherical joints with clearance on rigid-flexible dynamic of a space slider crank mechanism by finite element method. The model of the mechanism was designed by Solidworks and then velocity, acceleration, displacement, stress and contact force were determined by finite element analysis of rigid-transient dynamic in ANSYS. The results simulation indicated that the clearance size in revolute and spherical with clearance has sightly effected on the velocity of the slider, but has significantly effected on acceleration, contact force as journal and ball impact into bearing and socket with high peaks of acceleration and contact force as presented in the graph of acceleration and contact forces. The graph outlined that journal and ball motion with three types: free light, contact and impact motion. Clearance size created deviation for the displacement of the slider from 4.29 mm to 9.87 mm and maximum principal stress increases from 8.4 MPa to 10 MPa when clearance size increases from 0 mm to 0.3 mm.


2013 ◽  
Vol 376 ◽  
pp. 423-427 ◽  
Author(s):  
S. Prabhakaran ◽  
S. Ramachandran

Gearing is one of the most critical components in mechanical power transmission systems.. This paper explains about the comparison of the geometry of Helical gears for two different modules by modeling and mathematical equations, load distribution at various positions of the contact line and the stress analysis of Helical gears using three-dimensional finite element method. The bending stresses were examined using three-dimensional finite element model.. These stresses of different modules obtained from the finite element analysis were compared and the considerable reduction of weight occurred was found and also the values are compared with the theoretical values. Both results agree very well. This indicates that the finite element method model is accurate.


2021 ◽  
pp. 9-20
Author(s):  
A.V. Zaitsev ◽  
A.N. Izosimov

In the article, the modeling of the impact of hold-down forces on the accuracy of the shape of the workpiece using the finite element method was carried out. The operation of mechanical processing (turning cut) of a workpiece of the body of rotation type on a milling machine with basing and fixing along the inner cylindrical surface of the workpiece is considered. The study was conducted for four different types of machine retaining devices used on machines of this group. A consistent description and illustration of the method of modeling the process of the impact of hold-down forces on the workpiece is made for each type of the device under consideration. The force constraints and effects imposed on the model are described and illustrated, the parameters of the finite element grid used in modeling are presented, the displacement profiles obtained in the modeling process and the stages of modeling the machining process are described, and the values of the largest deviations from the shape of the workpiece are determined. The results of the modeling are presented: a qualitative picture of the shape errors obtained as a result of mechanical processing — the values of the largest deviation from the roundness and the largest deviation from the cross-section profile of the workpiece to be processed, as well as the shape of the cutting obtained in the cross-section of the workpiece for each type of the devices under consideration. On the basis of the obtained results, estimates of the degree of accuracy of the shape and the relative geometric accuracy provided by the considered devices were made in accordance with GOST 24643–81. The conclusion is made about the suitability of using the considered variants of machine retaining devices for the proposed technological process according to the criterion of the provided accuracy of the shape of the processed surface. English version of the article is available at URL: https://panor.ru/articles/modeling-the-influence-of-the-fastening-forces-on-the-accuracy-of-the-workpiece-shape-using-the-finite-element-method/65043.html


2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Lianming Cui ◽  
Min Wang ◽  
Tangrong Yu

A 1:1 flexible rock shed made of flexible nets and steel-vaulted structure is manufactured and tested for functional evaluation with impact experiment previously. To further discuss the performance of this structure under the impact of rockfalls and to improve the design, numerical simulation for this structure is carried out in this paper. Firstly, the simplified numerical models for characterizing the mechanical behavior of the ring nets and wire meshes are deduced. Then, a detailed finite element model for the flexible rock shed is developed for impact analysis. By comparing the experimental data, the numerical model for the flexible rock shed is shown to be reliable in predicting the dynamic behavior of the flexible rock shed. Finally, combined with the numerical simulation results and experimental results, an improved design is presented, and the numerical simulation results show that the energy dispersion in the improved design of the rock shed is more equalized, and damages on the steel-vaulted structure are much improved.


2015 ◽  
Vol 752-753 ◽  
pp. 769-772
Author(s):  
Hyun Bum Park

In this work, study on impact damage FEM model of composite sandwich structure was performed. Sandwich structure configuration is made of carbon-epoxy face sheets and foam cores. From the finite element method analysis results of sandwich composite structure, it was confirmed that the results of analysis was reasonable. The velocity of impactor to initiate damage was estimated, and in order to investigate the damage at the predicted velocity, impact analysis using finite element method was performed. According to the impact analysis results of sandwich structure, it was confirmed that the damage was generated at the estimated impact velocity. Finally, the comparison of the numerical results with those measured by the experiment showed good agreement.


2013 ◽  
Vol 275-277 ◽  
pp. 2241-2247 ◽  
Author(s):  
Arbtip Dheeravongkit ◽  
Narongsak Tirasuntarakul

Ball swaging is a general method in head stack assembly process to permanently attach Head Gimbal Assemblies (HGA) on the actuator arm. In this process, the swage ball is guided by a pin through the inner base plate’s hole in order to deform the base plate to tightly attach to the actuator arm. However, the loosing problem can still be found quite often in the current swaging process. This research focuses on ball sizes and the number of balls used which currently no theoretical guidance in choosing the both parameters. Besides, the best combination of the both parameters can give the best swaging performance. The three-dimensional finite element model is created and analyzed to estimate the swaging performance according to the variation of both parameters by using the tightening torque and the fixing distance of base plate to determine the quality of the ball swaging process. The results from finite element method are treated as the sampling points which are used to create the interpolation in order to increase the considered cases to cover all happening cases from both parameters. After that, a searching algorithm is implemented to determine the most suitable ball size and the number of ball used for the process. By using the finite element analysis together with the interpolation and a searching algorithm, the optimal design parameters for a complex problem with multiple conditions of consideration can be easily found.


2016 ◽  
Vol 2 (9) ◽  
Author(s):  
Amita Saxena ◽  
Ashish Kumar Sinha

The connecting rod is the intermediate member between the piston and the Crankshaft. Its primary function is to transmit the push and pull from the piston pin to the crank pin, thus converting the reciprocating motion of the piston into rotary motion of the crank. Existing connecting rod is manufactured by using Carbon steel. The axial stresses are produced due to cylinder gas pressure (compressive only) and the inertia force arising in account of reciprocating action (both tensile as well as compressive), where as bending stresses are caused due to the centrifugal effects. The result of which is, the maximum stresses are developed at the fillet section of the big and the small end. Hence, the project deals with the stress analysis of connecting rod by Finite Element Method ANSYS WORKBENCH 16.0 Software. The main objective in this paper to review on design evaluation and optimization of connecting rod parameters by using finite element method is to achieve suitable design for connecting rod. That can be achieved by changing such design parameters in the existing design. Finite element analysis of single cylinder four stroke petrol engines is taken for the study; Structural systems of Connecting rod can be easily analyzed using Finite Element techniques. So firstly a proper Finite Element Model is developed using CAD software. Then static and dynamic analysis is done to determine the von Misses stress, shear stress, elastic strain, total deformation in the present design connecting rod for the given loading conditions using Finite Element Analysis Software ANSYS v 16.In the first part of the study, the static and dynamic loads acting on the connecting rod, After that the work is carried out for safe design. Based on the observations of the static FEA and the load analysis results, the load for the optimization study was selected. The results were also used to determine of various stress and the fatigue model to be used for analyzing the fatigue strength. Outputs of the fatigue analysis of include fatigue life, damage, factor of safety, stress biaxiality indication. Then results of present model in ANSYS 16.0 are compared with the results of existing design in the reference paper.


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