scholarly journals An Improved Approach to Direct Simulation of an Actual Almen Shot Peening Intensity Test with a Large Number of Shots

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5088
Author(s):  
Chengyu Wang ◽  
Weigang Li ◽  
Jianjun Jiang ◽  
Xin Chao ◽  
Weikui Zeng ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Process Parameters ◽  
Element Model ◽  
Present Approach ◽  
Movement Speed ◽  
Plastic Layer ◽  
Surface Plastic ◽  
Transverse Deformation ◽  
Almen Intensity

In existing simulations of the Almen intensity test, arc height is indirectly obtained by an equivalent method including a representative cell, a few shots and equivalent loading. Most of these equivalent methods cannot consider the transverse deformation of the strip, the complex stress state of the plastic hardening layer and process parameters, resulting in deviation from the actual test. This paper introduces an improved and experimentally validated discrete element model (DEM)-finite element model (FEM) to predict the actual Almen intensity. The improvement of this model is mainly reflected in the large and real number of shots involved in the actual Almen intensity test, shot–shot interactions, and real-size solid finite element model of the Almen strip. A new method for calculating the shot stream is proposed based on the test and considering test process parameters such as the mass flowrate, nozzle movement speed and nozzle–workpiece distance. The shot stream impacting the strip with a fully restrained underside was first simulated in improved DEM-FEM to bring the forming energy. As a second step, an implicit solver of the Almen strip FEM calculates the spring-back to simulate strip removal from the holder. The results achieved by the present approach are compared with the results obtained by the experimental results and those in the literature. The results show that the arc height and Almen intensity obtained by the present approach match much better with the literature than the traditional method. Some new results obtained by the improved coupling DEM-FEM method are presented. The influences of the transverse deformation and surface plastic layer on the deformation of the Almen strip are discussed. This improved method provides an alternative characterization method for precision peen forming simulation.

Numerical and Experimental Analysis of Self Piercing Riveting Process with Carbon Fiber-Reinforced Plastic and Aluminium Sheets

2013 ◽  
Vol 554-557 ◽  
pp. 1045-1054 ◽  
Author(s):  
Welf Guntram Drossel ◽  
Reinhard Mauermann ◽  
Raik Grützner ◽  
Danilo Mattheß
Keyword(s):  
Finite Element ◽  
Carbon Fiber ◽  
Finite Element Model ◽  
Simulation Model ◽  
Process Parameters ◽  
Process Model ◽  
Element Model ◽  
Model Parameters ◽  
Fiber Reinforced ◽  
Carbon Fiber Reinforced

In this study a numerical simulation model was designed for representing the joining process of carbon fiber-reinforced plastics (CFRP) and aluminum alloy with semi-tubular self-piercing rivet. The first step towards this goal is to analyze the piercing process of CFRP numerical and experimental. Thereby the essential process parameters, tool geometries and material characteristics are determined and in finite element model represented. Subsequently the finite element model will be verified and calibrated by experimental studies. The next step is the integration of the calibrated model parameters from the piercing process in the extensive simulation model of self-piercing rivet process. The comparison between the measured and computed values, e.g. process parameters and the geometrical connection characteristics, shows the reached quality of the process model. The presented method provides an experimental reliable characterization of the damage of the composite material and an evaluation of the connection performances, regarding the anisotropic property of CFRP.

The Rolling Force Analysis of Closed Ring Rolling High-Neck Flange

2012 ◽  
Vol 201-202 ◽  
pp. 1130-1134
Author(s):  
Wen Fei Peng ◽  
Jing Jing Liang ◽  
Xue Dao Shu ◽  
Bao Shou Sun ◽  
Min Xiao
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Process Parameters ◽  
Rotational Speed ◽  
Rolling Force ◽  
Element Model ◽  
Ring Rolling ◽  
Force Analysis ◽  
Closed Ring ◽  
Feeding Speed

The rolling force will directly have influence on the size of high-neck flange and whether the rolled part will be shaped successfully. Finite element model of closed ring rolling high-neck flange was established, the effect of process parameters on rolling force and its reasons are analyzed. The results show that, the higher feeding speed is, the larger the amplification of rolling force will be, in addition, rolling force will be reduced slightly with the increase of rotational speed of driving roller, and the influence on the rolling force of compressing roller’s feeding speed is much larger than driving roller’s rotational speed.

A Method to Optimize Aluminum Alloy Door Impact Beam Stamping Process Using NSGA-II

2013 ◽  
Vol 773-774 ◽  
pp. 89-94 ◽  
Author(s):  
Jing Zhou ◽  
Bao Yu Wang ◽  
Lei Fu ◽  
Qing Lei Meng
Keyword(s):  
Genetic Algorithm ◽  
Finite Element ◽  
Finite Element Model ◽  
Process Parameters ◽  
Hot Stamping ◽  
Element Model ◽  
Quality Indices ◽  
Nsga Ii ◽  
Forming Quality ◽  
Data Points

The process parameters of aluminium alloy hot stamping produce an importantly effect on production forming quality. In the case of a door impact beam inside the car doors, the fi-nite-element model of aluminium alloy hot stamping is set up. Based on the model, the forming quality is investigated under usual process condition. Using the Latin hypercube method, we sampled the data points from design space of process parameters. Data points are imported into finite-element model to calculate the forming quality indices. According to their responding values, the quadratic response surfaces between process parameter inputs and forming quality indices are initialized. By optimized the response of the process parameters exercising multi-objective genetic algorithm—NSGA-II (non-dominated sorting genetic algorithm), the Pareto combinations of blank hold force and stamping velocity are obtained. Finally, by comparison with the results of stamping trial and numerical simula-tion, it is concluded that the finite-element model can be used to predict forming defects and is consistent with actual condition. Thus the optimization method is feasible.

scholarly journals Finite Element Analysis of Forward Slip in Micro Flexible Rolling of Thin Aluminium Strips

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1062 ◽  
Author(s):  
Feijun Qu ◽  
Jianzhong Xu ◽  
Zhengyi Jiang
Keyword(s):  
Grain Size ◽  
Finite Element ◽  
Finite Element Model ◽  
Process Parameters ◽  
Element Model ◽  
Rolled Strip ◽  
Forward Slip ◽  
Flexible Rolling ◽  
Multilinear Regression Analysis ◽  
Simulation Results

This study delineates a novel finite element model to consider a pattern of process parameters affecting the forward slip in micro flexible rolling, which focuses on the thickness transition area of the rolled strip with thickness in the micrometre range. According to the strip marking method, the forward slip is obtained by comparison between the distance of the bumped ridges on the roll and that of the markings indented by the ridges, which not only simplifies the calculation process, but also maintains the accuracy as compared with theoretical estimates. The simulation results identify the qualitative and quantitative variations of forward slip with regard to the variations in the reduction, rolling speed, estimated friction coefficient and the ratio of strip thickness to grain size, respectively, which also locate the cases wherein the relative sliding happens between the strip and the roll. The developed grain-based finite element model featuring 3D Voronoi tessellations allows for the investigation of the scatter effect of forward slip, which gets strengthened by the enhanced effect of every single grain attributed to the dispersion of fewer grains in a thinner strip with respect to constant grain size. The multilinear regression analysis is performed to establish a statistical model based upon the simulation results, which has been proven to be accurate in quantitatively describing the relationship between the forward slip and the aforementioned process parameters by considering both correlation and error analyses. The magnitudes of each process parameter affecting forward slip are also determined by variance analysis.

Numerical and Experimental Investigation of Process Parameters Effect of Low Carbon Steel Wire Produced with Roll Drawing Process

2011 ◽  
Vol 473 ◽  
pp. 113-120 ◽  
Author(s):  
Francesco Lambiase ◽  
Antoniomaria di Ilio
Keyword(s):  
Finite Element ◽  
Carbon Steel ◽  
Finite Element Model ◽  
Process Parameters ◽  
Low Carbon Steel ◽  
Experimental Tests ◽  
Element Model ◽  
Main Process ◽  
Drawing Process ◽  
Low Carbon

The effect of roll drawing process parameters on geometrical characteristics of flat roll draw wires is analyzed. Low carbon steel wires AISI 1010 are used in the experimental tests to assess the final geometry, mainly characterized by the width of flat wires, varying among several experimental levels the main process parameters i.e., initial wire dimensions, height reduction and lubrication conditions. Design of experiment technique was used to define the experimental plan and statistical techniques, such as analysis of mean (ANOM) and variance (AVOVA), were used to evaluate the effective influence of previous cited process parameters on final geometry of wire. A finite element model is developed to investigate a further process parameter i.e. the working rolls dimensions. In order to validate the finite element model, a campaign of experimental tests was conducted and the geometrical predictions of FE model were compared with experimental mea-surements with particular attention to final wire width, width of contact area and wire elongation. A linear regression analysis was performed and an empirical formulation to forecast the lateral spread of wire according to the main process parameters was developed.

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