Finite Element Analysis of Machining Thin-Wall Parts

2010 ◽  
Vol 458 ◽  
pp. 283-288 ◽  
Author(s):  
R. Izamshah R.A. ◽  
John Mo ◽  
Song Lin Ding

In an attempt to decrease weight, new commercial and military aircraft are designs with unitised monolithic metal structural components which contains of thinner ribs (i.e., walls) and webs (i.e., floors). Most of the unitised monolithic metal structural components are machined from solid plate or forgings with the start-to-finish weight ratio of 20:1. The resulting thin-walled structure often suffers a deformation which causes a dimensional surface error due to the action of the cutting force generated during the machining process. To alleviate the resulting surface errors, current practices rely on machining through repetitive feeding several times and manual calibration which resulting in long cycle times, low productivity and high operating cost. A finite element analysis (FEA) machining model is developed in this project to specifically predict the distortion or deflection of the part during end milling process. The model aims to provide an input for downstream decision making on error compensation strategy when machining a thin-wall unitised monolithic metal structural components. A set of machining tests have been done in order to validate the accuracy of the model and the results between simulation and experiment are found in a good agreement.

Author(s):  
Reza Madoliat ◽  
Sajad Hayati

This paper primarily deals with suppression of chatter in end-milling process. Improving the damping is one way to achieve higher stability for machining process. For this purpose a damper is proposed that is composed of a core and a multi fingered hollow cylinder which are shrink fitted in each other and their combination is shrink fitted inside an axial hole along the tool axis. This structure causes a resisting friction stress during bending vibration. Using FEA-ANSYS the structure is simulated. Then a parameter study is carried out where the frequency response and the depth of cut are calculated and tabulated to obtain the most effective configuration. The optimal configuration of tool is fabricated and finite element results are validated using modal test. The results show a high improvement in performance of the tool with proposed damper. Good agreement between experiments and modeling is obtained.


Micromachines ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 578 ◽  
Author(s):  
Bingrui Lv ◽  
Guilian Wang ◽  
Bin Li ◽  
Haibo Zhou ◽  
Yahui Hu

This paper describes the innovative design of a three-dimensional (3D) motion device based on a flexible mechanism, which is used primarily to produce accurate and fast micro-displacement. For example, the rapid contact and separation of the tool and the workpiece are realized by the operation of the 3D motion device in the machining process. This paper mainly concerns the device performance. A theoretical model for the static performance of the device was established using the matrix-based compliance modeling (MCM) method, and the static characteristics of the device were numerically simulated by finite element analysis (FEA). The Lagrangian principle and the finite element analysis method for device dynamics are used for prediction to obtain the natural frequency of the device. Under no-load conditions, the dynamic response performance and linear motion performance of the three directions were tested and analyzed with different input signals, and three sets of vibration trajectories were obtained. Finally, the scratching experiment was carried out. The detection of the workpiece reveals a pronounced periodic texture on the surface, which verifies that the vibration device can generate an ideal 3D vibration trajectory.


1999 ◽  
Author(s):  
V. Madhavan ◽  
L. Olovsson ◽  
S. C. Swargam ◽  
R. Agarwal

Abstract We describe here the development and testing of a capability for finite element simulation of practical machining operations such as turning and milling, using 3D multi-material, explicit dynamic, Eulerian finite element analysis. In these simulations the workpiece material and the air surrounding it are modeled using Eulerian finite elements and the flow of the workpiece material into the air as a result of the action of the Lagrangian tool can be freely tracked. Tension tests and Taylor impact tests are simulated using the traditional Lagrangian approach as well as the Eulerian approach. Comparison of the results is used to understand the factors affecting the solution accuracy. Simulations of orthogonal machining using this technique show that the side flow of the chip is simulated realistically. Simulations of oblique machining with various rake and inclination angles confirm that the chip flow angle is independent of the rake angle. Inertial effects cause the chip flow angle to differ from the inclination angle as the weight of the chip increases. Simulations of turning and end milling show that chip formation and flow can be simulated ab-initio. The simulation capability described here can provide accurate results for various outputs of interest and is also computationally efficient, allowing a typical analysis to be completed within a day.


Author(s):  
Saurabh Srivastava ◽  
Sachin Salunkhe ◽  
Sarang Pande ◽  
Bhavin Kapadiya

Steering knuckle connects steering system, suspension system and braking system to the chassis. The steering knuckle contributes a significant weight to the total weight of a vehicle. Increasing the efficiency of an automobile without compromising the performances is the major challenge faced by the manufacturers. This paper presents an effective topology optimization of steering knuckle used in a vehicle with the primary objective of minimizing weight. The study on optimization of knuckle is divided into two phases, the first phase involves making of a computer-aided design model of the original steering knuckle and carry out finite element analysis on the knuckle by estimating the loads, which are acting on the component. In the second phase, design optimization of the model of steering knuckle is carried out, and excess material is removed at the region where induced stress is negligible as obtained in finite element analysis assuming standard boundary and loading conditions. The paper describes a research work carried out to optimize structural topology giving the essential details. The methodology may be applied to optimize structural components used in applications where the ratio of desired properties to the cost, generally in terms of weight, is to be optimized. In the case of automobiles, strength to weight ratio has to be maximized. New researchers working in the area will have an understanding of the procedures, and further, the techniques may be applied to design in general.


2011 ◽  
Vol 87 ◽  
pp. 106-112 ◽  
Author(s):  
Amiri Asfarjani Alireza ◽  
Adibnazari Sayid ◽  
Reza Kashyzadeh Kazem

Fibrous composites are finding more and more applications in aerospace, automotive, and naval industries. They have high stiffness and strength to weight ratio and good rating in regards to life time fatigue. Investigating mechanical behavior under dynamic loads to replace this material is very important. In the present article, investigate Fatigue of Unidirectional Fibrous Composites by using finite element analysis. So, to achieve this purpose Firstly, modeling fiber and matrix in separate case and simulated semi actual conditions, attained S-N curve of fiber and matrix and after that by using micromechanical model of combination fiber and matrix can approach S-N curve of Unidirectional Fibrous Composites. Finally, Comparisons of the finite element analysis of Ansys and the experimental predictions indicate based on three point bending fatigue testing that the results are satisfactorily in good agreement with each other which approves the power law assumption in the model.


2014 ◽  
Vol 694 ◽  
pp. 279-282
Author(s):  
Qi Liu ◽  
Hang Guo ◽  
Wei Wang ◽  
Yu Ting Wu ◽  
Fang Ye ◽  
...  

In the process of shell design of a 100kW single screw expander, the fundamental research on the screw chamber walls thickness is still lacking. Thin wall may cause deformation and the damage possibility of the inlet passage. Thick wall will increase the weight of the expander and led to assembly problem and transportation inconvenience. In this paper, static finite element analysis on cast shell of the 100 kW single screw expander was carried out. By calculating stress distribution and deformation of the expander shell under 1.5 times of the design pressure, the authors find the thickness of gate rotor chamber walls and inlet passage walls as 15 mm is acceptable, but the thickness of screw chamber walls should be at least 35 mm.


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