scholarly journals Numerical Simulation and Experimental Study on the Drilling Process of 7075-t6 Aerospace Aluminum Alloy

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 553
Author(s):  
Haitao Luo ◽  
Jia Fu ◽  
Tingke Wu ◽  
Ning Chen ◽  
Huadong Li

A finite element model for setting drilling conditions is established. The effect of feed speed and spindle speed on the drilling process was studied. In the test phase, drilling tests were conducted using three different feed speeds (60, 100, and 140 mm/min) and three different spindle speeds (800, 1000, and 1200 rpm). The correctness of the finite element model was verified by comparing the experimental and numerical simulation data. The results show that the axial force and torque increase significantly with the increase of feed speed, while the axial force and torque increase less as the spindle speed increases. The numerical simulation results show that the temperature of the cutting edge increases as the feed speed increases. Increasing the rotating speed increases the formation of chip curl. When the working conditions are high rotating speed and low feed, the tool wear is reduced, and the machining quality is better. The numerical simulation results obtained for the chip forming effect are similar to the experimental data. In addition, the simulation results show the generation of burrs. A comparison of the finite element simulation and experimental data leads to an in-depth understanding of the drilling process and ability to optimize subsequent drilling parameters, which provide reliable process parameters and technical guarantees for the successful implementation of drilling technology for space suspended ball structures.

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 875
Author(s):  
Jie Wu ◽  
Yuri Hovanski ◽  
Michael Miles

A finite element model is proposed to investigate the effect of thickness differential on Limiting Dome Height (LDH) testing of aluminum tailor-welded blanks. The numerical model is validated via comparison of the equivalent plastic strain and displacement distribution between the simulation results and the experimental data. The normalized equivalent plastic strain and normalized LDH values are proposed as a means of quantifying the influence of thickness differential for a variety of different ratios. Increasing thickness differential was found to decrease the normalized equivalent plastic strain and normalized LDH values, this providing an evaluation of blank formability.


2010 ◽  
Vol 20-23 ◽  
pp. 1405-1408 ◽  
Author(s):  
Wei Hua Kuang ◽  
Qun Liu

Drawing process is an important technology in shaping products. In the paper, the geometric surfaces of tools and sheet were modeled by Pro/E software, and a 3D finite element model of the cylindrical drawing process was developed by DYNAFORM. Numerical simulation results showed the distribution of stress, strain and thickness. FLD showed no material was in crack area and risk crack area. The drawing process could be successfully completed in one stroke. The simulation results were helpful for the die design.


2021 ◽  
Author(s):  
Hussain AlBahrani ◽  
Nobuo Morita

Abstract In many drilling scenarios that include deep wells and highly stressed environments, the mud weight required to completely prevent wellbore instability can be impractically high. In such cases, what is known as risk-controlled wellbore stability criterion is introduced. This criterion allows for a certain level of wellbore instability to take place. This means that the mud weight calculated using this criterion will only constrain wellbore instability to a certain manageable level, hence the name risk-controlled. Conventionally, the allowable level of wellbore instability in this type of models has always been based on the magnitude of the breakout angle. However, wellbore enlargements, as seen in calipers and image logs, can be highly irregular in terms of its distribution around the wellbore. This irregularity means that risk-controlling the wellbore instability through the breakout angle might not be always sufficient. Instead, the total volume of cavings is introduced as the risk control parameter for wellbore instability. Unlike the breakout angle, the total volume of cavings can be coupled with a suitable hydraulics model to determine the threshold of manageable instability. The expected total volume of cavings is determined using a machine learning (ML) assisted 3D elasto-plastic finite element model (FEM). The FEM works to model the interval of interest, which eventually provides a description of the stress distribution around the wellbore. The ML algorithm works to learn the patterns and limits of rock failure in a supervised training manner based on the wellbore enlargement seen in calipers and image logs from nearby offset wells. Combing the FEM output with the ML algorithm leads to an accurate prediction of shear failure zones. The model is able to predict both the radial and circumferential distribution of enlargements at any mud weight and stress regime, which leads to a determination of the expected total volume of cavings. The model implementation is first validated through experimental data. The experimental data is based on true-triaxial tests of bored core samples. Next, a full dataset from offset wells is used to populate and train the model. The trained model is then used to produce estimations of risk-controlled stability mud weights for different drilling scenarios. The model results are compared against those produced by conventional methods. Finally, both the FEM-ML model and the conventional methods results are compared against the drilling experience of the offset wells. This methodology provides a more comprehensive and new solution to risk controlling wellbore instability. It relies on a novel process which learns rock failure from calipers and image logs.


2001 ◽  
Author(s):  
Y. W. Kwon ◽  
J. A. Lobuono

Abstract The objective of this study is to develop a finite element model of the human thorax with a protective body armor system so that the model can adequately determine the thorax’s biodynamical response from a projectile impact. The finite element model of the human thorax consists of the thoracic skeleton, heart, lungs, major arteries, major veins, trachea, and bronchi. The finite element model of the human thorax is validated by comparing the model’s results to experimental data obtained from cadavers wearing a protective body armor system undergoing a projectile impact.


Author(s):  
Lý Hùng Anh ◽  
Nguyễn Phụ Thượng Lưu ◽  
Nguyễn Thiên Phú ◽  
Trần Đình Nhật

The experimental method used in a frontal crash of cars costs much time and expense. Therefore, numerical simulation in crashworthiness is widely applied in the world. The completed car models contain a lot of parts which provided complicated structure, especially the rear of car models do not contribute to behavior of frontal crash which usually evaluates injuries of pedestrian or motorcyclist. In order to save time and resources, a simplification of the car models for research simulations is essential with the goal of reducing approximately 50% of car model elements and nodes. This study aims to construct the finite element models of front structures of vehicle based on the original finite element models. Those new car models must be maintained important values such as mass and center of gravity position. By using condition boundaries, inertia moment is kept unchanged on new model. The original car models, which are provided by the National Crash Analysis Center (NCAC), validated by using results from experimental crash tests. The modified (simplistic) vehicle FE models are validated by comparing simulation results with experimental data and simulation results of the original vehicle finite element models. LS-Dyna software provides convenient tools and very strong to modify finite element model. There are six car models reconstructed in this research, including 1 Pick-up, 2 SUV and 3 Sedan. Because car models were not the main object to evaluate in a crash, energy and behavior of frontal part have the most important role. As a result, six simplified car models gave reasonable outcomes and reduced significantly the number of nodes and elements. Therefore, the simulation time is also reduced a lot. Simplified car models can be applied to the upcoming frontal simulations.


2013 ◽  
Vol 838-841 ◽  
pp. 458-461
Author(s):  
Jing Cui ◽  
Ling Feng Yin ◽  
Xiao Ming Guo ◽  
Gan Tang ◽  
Tian Jiao Jin

Based on the fire tests of WILLIAMS double-poles structure, considering the dual nonlinear interaction of material and geometric, established one complete finite element model of grid structure. For the performance that the physical and mechanics properties of steel will degrade while the temperature arising, simulate the test models with ANSYS, get a better numerical results, proof the numerical method is feasible.


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