Methods, Models, and Assumptions Used in Finite Element Simulation of a Pilger Metal Forming Process

Author(s):  
John Martin

The pilger process is a cold-worked mechanical process that combines the elements of extrusion, rolling, and upsetting for the formation of thin-walled tubes. This complex manufacturing process relies on the results of trial and error testing programs, experimental parameter sensitivity studies, and prototypical applications to advance the technology. This finite element modelling effort describes the methods, models, and assumptions used to assess the process parameters used to manufacture thin-walled tubing. The modelling technique breaks down the manufacturing process into smaller computer generated models representing fundamental process functions. Each of these models is linked with the overall process simulation. Simplified assumptions are identified and supporting justifications provided. This work represents proof of principle modelling techniques, using large deformation, large strain, finite element software. These modelling techniques can be extended to more extensive parameter studies evaluating the effects of pilger process parameter changes on final tube stress and strain states and their relationship to defect formation/propagation. Sensitivity studies on input variables and the process parameters associated with one pass of the pilger process are also included. The modelling techniques have been extended to parameter studies evaluating the effects of pilger process parameter changes on tube stress and strain states and their relationship to defect formation. Eventually a complex qualified 3-D model will provide more accurate results for process evaluation purposes. However, the trends and results reported are judged adequate for examining process trends and parameter variability.

2010 ◽  
Vol 102-104 ◽  
pp. 7-11
Author(s):  
Cong Da Lu ◽  
Yi Lian Zhang ◽  
Shao Fei Jiang ◽  
Guo Zhong Chai

In this paper, the main molding process parameters which are relevant to warpage were optimized by orthogonal experiment and finite element software MPI. The result shows that we can get a series of optimized parameters and know how much each process parameter influences the warpage by combining orthogonal experiments with simulation experiments using MPI, while fewer experiments are needed. Verified by MPI, such series of optimized parameters can keep the warpage in a low level and completely meet the standard of the product.


2021 ◽  
Vol 2083 (4) ◽  
pp. 042057
Author(s):  
Ziqian Zhang ◽  
Ying Zhong

Abstract The section flattening phenomenon (namely Bazier effect) will occur in the large bending deformation stage of thin-walled pipe in the continuous straightening process. The maximum section flattening amount and the residual section flattening amount are important process parameters, which are the basis for calculating the subsequent process parameters of the flattening circle, and directly determine the roundness of the final pipe and the product quality. However, it is hard to be obtained by the theoretical or experimental methods. Therefore, based on the structure and process parameters of the leveler, a finite element model was built to simulate the section flattening process. Then, ANSYS/LS-DYNA software was used to dynamically simulate the bending flattening phenomenon of thin-walled pipe in the continuous straightening process, and the stress and strain nephographic of the flattening deformation zone was obtained. By recording the position curve of the key nodes in the preventing process, the section flattening amount of the thin-walled pipe in the large bending deformation stage in the continuous straightening process was determined. The simulation results show that the dynamic simulation method can effectively predict the section flattening of thin-walled pipe in the process of continuous straightening.


Author(s):  
Ainhoa Martinez Ormaetxea ◽  
Andreas Öchsner

The manufacturing process of bone scaffold structures has an important influence on the final mechanical strength of the structure. When the structures are not produced properly, i.e. have imperfections such as missing parts or slightly displaced joints, they lose some of their mechanical properties. The aim of this study was to see how different types of damage affect the structures and also if their effects are equal when the structure is subjected to different load conditions. The change of the mechanical behavior was determined using the commercial finite element software MSC Marc Mentat. In turn, the damage was introduced by manipulating the structure’s files (ASCII data files) using the programming language Fortran. Apart from the numerical simulations, experimental testing was also performed to verify the numerical results. In the frame of this study, useful information for further research is provided.


Author(s):  
Zengliang Hao ◽  
Junting Luo ◽  
Yongbo Jin ◽  
Jinheng Liu ◽  
Zhenjie Wang ◽  
...  

A one-pass annealing–internal spinning is proposed to form a conical thin-walled shell with large curved generatrix. The structure of the blank used is designed based on product-size requirements. ABAQUS finite element software is used to simulate the internal spinning process of a conical thin-walled shell with large curved generatrix under small-end (process 1) and large-end (process 2) rotations. The microstructure of the products is subsequently analyzed. Results show that the spinning pressure of the skin part under process 1 is relatively stable, and that the strain and residual stress distribution are uniform, and the hardness and the mechanical performance is improved. The products of the two processes have an obvious circumferential fiber structure. The second phase grain size in the fracture morphology of the product formed under the process 1 is uniform, and its size is in the range of 2–6 µm. Whereas, the second phase distribution of the product formed under the process 2 is not uniform, the fine second phase grain size is in 1–2 µm, and the coarse second phase grain size is in 5–8 µm.


2012 ◽  
Vol 622-623 ◽  
pp. 1140-1142
Author(s):  
Li Mei Wu ◽  
Yong Zhao Li ◽  
Yan Rong Wang ◽  
Fei Yang

Taking taper-lock Connection in Wind Turbine Spindle as research object, the paper analyzes the relativity of structural sizes and builds the parametric structural model by means of a way APDL. By using the non-liner finite element software ANSYS, the stress of taper-lock on the limit load conditions is analyzed, then contact stress and strain of the planet carrier and spindle are discussed. This is useful to the choice of assembly condition during taper-lock, planet carrier and spindle and providing theoretical data.


2015 ◽  
Vol 41 (2) ◽  
pp. e12-e18 ◽  
Author(s):  
Mostafa Omran Hussein ◽  
Mahmoud Elsayed Rabie

The All-on-4 design was used successfully for restoring edentulous mandible. This design avoids anatomic cripples such as inferior alveolar nerve by tilting posterior implants. Moreover, tilting posterior implants of All-on-4 design had a mechanical preference than the conventional design. On the other hand, the anterior implants are parallel at the lateral incisor region. Several researches showed favorable results for tilting posterior implants. However, research did not study the influence of the anterior implant position or orientation on the mechanical aspects of this design. This study analyzes the influence of varying anterior implant position and orientation of the All-on-4 design using nonlinear contact 3D finite-element analysis. Three copied 3-dimensional models of the All-on-4 design were classified according to anterior implant position and orientation. The frictional contact between fixtures and bone was the contact type in this finite element analysis. Finally, von Mises stress and strain at implant and bone levels were recorded and analyzed using finite element software. Stress concentrations were detected mainly around the posterior implant at the loaded side. Values of the maximum equivalent stress and strain were around tilted implants of design III followed by design II, then design I. Changing the position or orientation of the anterior implants in All-on-4 design influences stress-strain distribution of the whole design.


2013 ◽  
Vol 438-439 ◽  
pp. 1262-1264
Author(s):  
Ke Dong Tang ◽  
Feng Gui Jin

The river dam intends to build at 280m downstream of a built bridge. This paper, using ANSYS finite element software, establishes a rational and realistic model to analyze the influence of the reservoir construction on the thin-walled hollow pier of built bridge. The variation of the stress of the bridge thin-walled hollow pier before and after impounding of the reservoir is given out, which can be as a guidance for future reinforcing the thin-walled hollow pier.


2012 ◽  
Vol 557-559 ◽  
pp. 300-303
Author(s):  
Cheng Hong Duan ◽  
Xiang Peng Luo ◽  
Nan Zhang

In this paper, a finite element model of a composite gas cylinder was established by ABAQUS finite element software, with consideration that both heads were helically wound and their wound angle and wound thickness varied with different parallel circle radius. Stress of the composite gas cylinder and PEEQ of its liner under different working conditions after autofrettage treatment were studied, the stress distribution was assessed by the DOT CFFC standard and the effective range of autofrettage treatment was confirmed. This finite element analysis method may be referable to the design and inspection of composite gas cylinders.


2019 ◽  
Vol 64 (4) ◽  
pp. 1-15 ◽  
Author(s):  
Guillaume Seon ◽  
Yuri Nikishkov ◽  
Andrew Makeev ◽  
Lauren Fergusson

Composite helicopter rotor components are typically thick and often have areas with a tight radius of curvature, which make them especially prone to process-induced defects, including wrinkles and voids at ply interfaces. Such flaws cause high rejection rates in production of flight-critical components and structures. This work seeks to fill the gaps in understanding generation of the noted defects in contoured polymer–matrix composite laminates. In particular, understanding and modeling defect formation at the early stages of the manufacturing process might be the missing link to enable the development of practical engineering solutions allowing for better control of the manufacturing process of contoured composite parts. In this work, an approach based on a continuum description of the uncured prepreg material, including the initial bulk or void content, and finite element modeling (FEM) is used to simulate the consolidation process at the early stages of manufacturing of contoured laminates. The simulation predicts instabilities leading to formation of both wrinkles and voids at ply interfaces during laminate debulking or vacuum consolidation. Applicability of the method to consolidation in both closed-cavity and open-face tooling is also demonstrated. FEM results show good correlation with X-ray computed tomography data. This work also introduces a new simulation concept based on finite element and discrete modeling of voids at ply interfaces to improve the accuracy of predicting their evolution during the debulking operations.


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