Optimal Clamping Scheme of Thin-Walled Cavity Workpiece

2011 ◽  
Vol 189-193 ◽  
pp. 2116-2120
Author(s):  
Shi Min Geng ◽  
Jun Wang
Keyword(s):  
Finite Element ◽  
Aluminum Alloy ◽  
Machining Process ◽  
Machining Accuracy ◽  
Finite Element Models ◽  
Thin Walled ◽  
Clamping Sequence

The thin-walled cavity workpiece with insufficient rigid property is liable to deform during the machining process and the request of accuracy is very strict. The paper takes typical aeronautic aluminum-alloy for example, fixture is an important consideration in the operation. To reveal the influences of locating points, clamping sequence and loading ways on the distortion of thin-walled cavity part, finite element models were established to simulate the clamping operation. The result shows the preferable scheme is that the distance of the clamping locations are far each other, clamping forces are firstly applied on the surface with high rigid and all clamping forces are applied in many steps. The scheme can effectively control the deformation of clamp ,and furthermore improve the machining accuracy.

Study on Deformation of Thin-Walled Workpieces Milling Machining Based on Finite Element Method

2014 ◽  
Vol 644-650 ◽  
pp. 4971-4975
Author(s):  
Ji Qun Wang
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Thin Plate ◽  
Simulation Analysis ◽  
Geometric Model ◽  
Mode Selection ◽  
Machining Process ◽  
Machining Accuracy ◽  
Finite Element Numerical Simulation ◽  
Thin Walled

In the mechanical products, there are always some poor stiffness and high precision thin-walled workpieces which will produce deformation in the machining process easily, so it is difficult to control the machining accuracy and to meet the requirement of higher machining accuracy. Based the finite element numerical simulation key technology, this paper analyzes the machining deformation, including geometric model simplification, mode selection, dynamic loading, a 3D simulation model of thin plate features establishment. Through the finite element numerical simulation analysis of the thin plate, we analyze the influence on processing deformation from different processing parameters and different constraints.

On-Machine Estimation of Workpiece Deformation for Thin-Walled Parts Considering Fixture Clamping Sequence

2020 ◽  
Author(s):  
Jingkai Zeng ◽  
Koji Teramoto ◽  
Dongjin Wu ◽  
Hiroki Matsumoto
Keyword(s):  
Manufacturing Industry ◽  
Structural Characteristics ◽  
Process Variations ◽  
Point Of View ◽  
Machining Process ◽  
Machining Accuracy ◽  
Near Net Shape ◽  
Modern Manufacturing ◽  
Thin Walled ◽  
Clamping Sequence

Abstract Due to the higher structure efficiency and lightweight characteristic, thin-walled parts are widely used in the modern manufacturing industry. However, from another point of view, these parts are complex in structure, weak stiffness and high precision demand. During the machining process, because of the material properties and structural characteristics, the action of elastic deformation in machining is heavily affected by the accuracy of thin-walled parts. Recently, novel near-net-shape machining methods which can be applicable to small-lot production such as thin-walled casting, additive manufacturing, and so on becomes common technology. Finish machining of these thin-walled and complex shape workpiece is an important target of machining. In the small lot production, most of fixturing process is executed as manual operations, which generate large process variations. These variations lead to deteriorate machining accuracy. Especially, the wrong operation for the fixture clamping sequence generates different workpiece deformation. The objective of this research is to estimate actual workpiece deformation by utilizing locally measured strains and fixturing simulation in order to detect unallowable workpiece deformation caused by the wrong clamping sequence. In this research, workpiece deformations for different clamping sequences are evaluated based on the engineering experiments. Verifications of estimated workpiece deformations are carried out. Through this research, we can effectively estimate the workholding situation of the thin-walled parts during the machining process.

Experimental and numerical studies on failure and energy absorption of composite thin-walled square tubes under quasi-static compression loading

2020 ◽  
Vol 21 (6) ◽  
pp. 623-634
Author(s):  
Haolei Mou ◽  
Zhenyu Feng ◽  
Jiang Xie ◽  
Jun Zou ◽  
Kun Zhou
Keyword(s):  
Finite Element ◽  
Shell Model ◽  
Energy Absorption ◽  
Failure Mode ◽  
Failure Criterion ◽  
Finite Element Models ◽  
Static Compression ◽  
Compression Loading ◽  
Thin Walled ◽  
Simulation Results

AbstractTo analysis the failure and energy absorption of carbon fiber reinforced polymer (CFRP) thin-walled square tube, the quasi-static axial compression loading tests are conducted for [±45]3s square tube, and the square tube after test is scanned to further investigate the failure mechanism. Three different finite element models, i.e. single-layer shell model, multi-layer shell model and stacked shell mode, are developed by using the Puck 2000 matrix failure criterion and Yamada Sun fiber failure criterion, and three models are verified and compared according to the experimental energy absorption metrics. The experimental and simulation results show that the failure mode of [±45]3s square tube is the local buckling failure mode, and the energy are absorbed mainly by intralaminar and interlaminar delamination, fiber elastic deformation, fiber debonding and fracture, matrix deformation cracking and longitudinal crack propagation. Three different finite element models can reproduce the collapse behaviours of [±45]3s square tube to some extent, but the stacked shell model can better reproduce the failure mode, and the difference of specific energy absorption (SEA) is minimum, which shows the numerical simulation results are in better agreement with the test results.

scholarly journals The method of direct finite perturbation of numerical models for studying of the dynamic, stiffness and strength properties for thin-walled elements of engineering constructions.

2014 ◽  
Vol 2014 (4) ◽  
pp. 114-124
Author(s):  
Юрий Костенко ◽  
Yuriy Kostenko ◽  
Анатолий Чепурной ◽  
Anatoliy Chepurnoy ◽  
Александр Литвиненко ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Finite Element ◽  
Natural Frequencies ◽  
Numerical Models ◽  
Dynamic Stiffness ◽  
Strength Properties ◽  
Test Problems ◽  
Finite Element Models ◽  
Direct Perturbation ◽  
Thin Walled

The methods of direct perturbation for finite element models of thin-walled engineering constructions for sensitivity analysis of their strength, stiffness and dynamic characteristics to the change in their thickness are proposed. The approach for prediction of distribution for natural frequencies migration as result of change in their thickness are presented. The applicability of the linearized models to determine displacements, stresses and natural frequencies slightly thinned design compared to the nominal (original) are shown. The examples of test problems are given.

scholarly journals Increasing Damping of Thin-Walled Structures Using Additively Manufactured Vibration Eliminators

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2125 ◽  
Author(s):  
Paweł Dunaj ◽  
Stefan Berczyński ◽  
Karol Miądlicki ◽  
Izabela Irska ◽  
Beata Niesterowicz
Keyword(s):  
Finite Element ◽  
Dynamic Stiffness ◽  
Experimental Studies ◽  
Steel Beam ◽  
Finite Element Models ◽  
Fem Model ◽  
Thin Walled Structures ◽  
Resonance Frequencies ◽  
Thin Walled ◽  
Parametric Analyses

The paper presents a new way to conduct passive elimination of vibrations consisting of covering elements of structures with low dynamic stiffness with polylactide (PLA). The PLA cover was created in 3D printing technology. The PLA cover was connected with the structure by means of a press connection. Appropriate arrangement of the PLA cover allows us to significantly increase the dissipation properties of the structure. The paper presents parametric analyses of the influence of the thickness of the cover and its distribution on the increase of the dissipation properties of the structure. Both analyses were carried out using finite element models (FEM). The effectiveness of the proposed method of increasing damping and the accuracy of the developed FEM models was verified by experimental studies. As a result, it has been proven that the developed FEM model of a free-free steel beam covered with polylactide enables the mapping of resonance frequencies at a level not exceeding 0.6% of relative error. Therefore, on its basis, it is possible to determine the parameters of the PLA cover. Comparing a free-free steel beam without cover with its PLA-covered counterpart, a reduction in the amplitude levels of the receptance function was achieved by up to 90%. The solution was validated for a steel frame for which a 37% decrease in the amplitude of the receptance function was obtained.

Numerical Investigation on Weld-Induced Imperfections in Aluminum Ship Plates

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Bai-Qiao Chen ◽  
C. Guedes Soares
Keyword(s):  
Finite Element ◽  
Aluminum Alloy ◽  
Material Properties ◽  
Welding Process ◽  
Finite Element Models ◽  
Finite Element Analyses ◽  
Temperature Dependent ◽  
Military Applications ◽  
Structural Responses ◽  
Or In Military

The present work aims at better understanding and predicting the thermal and structural responses of aluminum components subjected to welding, contributing to the design and fabrication of aluminum ships such as catamarans, lifesaving boats, tourist ships, and fast ships used in transportation or in military applications. Taken into consideration the moving heat source in metal inert gas (MIG) welding, finite element models of plates made of aluminum alloy are established and validated against published experimental results. Considering the temperature-dependent thermal and mechanical properties of the aluminum alloy, thermo-elasto-plastic finite element analyses are performed to determine the size of the heat-affected zone (HAZ), the temperature histories, the distortions, and the distributions of residual stresses induced by the welding process. The effects of the material properties on the finite element analyses are discussed, and a simplified model is proposed to represent the material properties based on their values at room temperature.

Study the Influence of Geometric Parameters on Springback in T-Section Aluminum Alloy Window Trim Strip Sheets Forming

2018 ◽  
Vol 920 ◽  
pp. 70-76 ◽  
Author(s):  
Bao Hang Zhu ◽  
Yi Xi Zhao ◽  
Zhong Qi Yu ◽  
Hui Yan
Keyword(s):  
Finite Element ◽  
Aluminum Alloy ◽  
Geometric Parameters ◽  
Finite Element Models ◽  
Quality Requirement ◽  
Forming Process ◽  
Assembly Quality ◽  
Simulation Results ◽  
In The Beginning ◽  
Springback Control

The T-section aluminum alloy window trim strip sheets are used to improve vehicle appearance. As the mobile scenery line, these window trim strips with claws need high forming accuracy to meet good assembly quality requirement. The top portion of the T-section sheet is stamped to form an edge flange structure. Springback control is essential in forming process. In this paper, the influence of the window trim strip geometric parameters on forming springback is studied. Some finite element models of the process were built with the Dynaform software. The simulation results were verified experimentally. The main conclusions include as belows: The different heights of the stiffeners part in T-section change the stiffness of the part. Although the stiffeners part does not participate in the forming, it also has springback in the forming process. So, it is necessary to study the influence of the flanging part width (W) and the stiffeners part height (H) of the T-section on springback. We set W to 15 mm and change the value of H value according to the real product. The value of springback increases with the increase of H value in the beginning. After ratio of H/W increases to 0.6, the value of springback fluctuates with the increase of H value. When ratio of H/W is about 0.5, the springback values are mostly less than ± 0.5 mm in key sections, which is acceptable.

Influence of Sandwich Damping on the Loss Factor of Multi-Plies Bellows

2010 ◽  
Vol 44-47 ◽  
pp. 2998-3002 ◽  
Author(s):  
Wei Ma ◽  
Yong Chao Lu ◽  
Yong Gang Liu ◽  
Ji Shun Li ◽  
Yu Jun Xue
Keyword(s):  
Finite Element ◽  
Loss Factor ◽  
Strain Energy ◽  
Vibration Isolation ◽  
Mechanical Performance ◽  
Finite Element Models ◽  
Modal Strain Energy ◽  
Modal Strain Energy Method ◽  
Thin Walled ◽  
Strain Energy Method

Multi-plies bellows is a kind of cylindrical thin-walled container with curved shape. It is effective in seal, energy storage and vibration isolation. In the paper, the modal loss factor of multi-plies bellows was analyzed based on the modal strain energy method. Then the finite element models of multi-piles bellows were given by ANSYS. The mechanical performance of bellows was analyzed in detail. The strain energy distribution of multi-plies bellows and viscoelsticity layer were given. According to the strain energy, the influence of sandwich damping on the loss factor was studied. The results show that the loss factor can be improved by employing the sandwich damping with big thickness and elastic modulus 200MPa.

Analysis of Cutting Technologies for Lightweight Frame Components

2006 ◽  
Vol 10 ◽  
pp. 121-132 ◽  
Author(s):  
Klaus Weinert ◽  
Sven Grünert ◽  
Michael Kersting
Keyword(s):  
Finite Element ◽  
Metal Cutting ◽  
Thermal Stresses ◽  
Machining Process ◽  
Frame Structure ◽  
Experimental Investigations ◽  
Promising Alternative ◽  
Thin Walled ◽  
Process Strategy ◽  
Conventional Drilling

Most technical components applied in industrial practice are subjected to metal cutting operations during their production process. However, this leads to undesirable thermal and mechanical loads affecting the machined workpiece, which can result in an impairment of its serviceability. Due to their small wall thickness lightweight hollow profiles are highly susceptible to the inevitable machining loads and thermal stresses during drilling processes. For the virtual optimization of the machining process and in order to ensure a suitable process strategy, a finite element simulation of cutting operations for thin-walled light metal profiles is conducted. Due to the flexibility within creating drill holes of different diameters without tool changes circular milling represents a promising alternative to the application of conventional drilling tools for variable process strategies to handle batch sizes down to one piece efficiently. Hence, this article gives an insight into the investigations regarding the modeling concepts of the mechanical and thermal loads induced into the thin-walled lightweight frame structure during the circular milling process. Furthermore, process reliability aspects as well as the correlation of the calculated and the measured results will be discussed on the basis of experimental investigations. Finally, this article compares Finite Element Analysis aspects of circular milling processes with conventional drilling processes.

Research on Machining Accuracy in Milling Ti6Al4V Thin-Walled Component with Paraffin Reinforcement

2012 ◽  
Vol 268-270 ◽  
pp. 504-509
Author(s):  
Biao Gao ◽  
Jie Sun ◽  
Jian Feng Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Machining Accuracy ◽  
The Finite Element Method ◽  
Technical Problems ◽  
Low Stiffness ◽  
Thin Walled ◽  
Element Method

According to the technical problems such as low stiffness vibration and dimension error in milling Ti6Al4V thin-walled component, the manufacturing with paraffin reinforcement is studied. Firstly, paraffin formula for milling thin-walled component is researched. Secondly, applying the finite element method (FEM) to predict the deformation of machining with paraffin reinforcement and the corresponding milling experiments is done to check the the validity of the model. Finally, the influences of machining accuracy about different paraffin formulas for the same component are obtained. This study supplies support for the research of paraffin formula which are based on reducing the distortion of workpiece.

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