Investigation of Sheet-Titanium Forming with Flexible Tool – Experiment and Simulation / Badanie Kształtowania Blach Tytanowych Z Wykorzystaniem Elastycznego Narzędzia - Doświadczenie I Symulacja

2012 ◽  
Vol 57 (4) ◽  
pp. 1247-1252 ◽  
Author(s):  
J. Adamus ◽  
P. Lacki

In the paper the results of investigation of sheet-titanium forming with flexible tool are presented. Titanium alloy sheets belong to a group of materials which are very hard to deform at ambient temperature. To improve sheet formability forming technology using a semi-flexible tool was implemented. Experiments were carried out on a specially designed for this purpose device. Due to the application of a rubber pad the stress state similar to triaxial compression was produced in the deformed material. Such a stress state made it possible to obtain higher material deformation without risk of fracture. The numerical simulations were used for analysing the flexible forming process. The ADINA System basing on the Finite Element Method (FEM) was applied.

Author(s):  
Shiro Kobayashi ◽  
Soo-Ik Oh ◽  
Taylan Altan

The application of computer-aided design and manufacturing techniques is becoming essential in modern metal-forming technology. Thus process modeling for the determination of deformation mechanics has been a major concern in research . In light of these developments, the finite element method--a technique by which an object is decomposed into pieces and treated as isolated, interacting sections--has steadily assumed increased importance. This volume addresses advances in modern metal-forming technology, computer-aided design and engineering, and the finite element method.


2017 ◽  
Vol 746 ◽  
pp. 3-9
Author(s):  
Vladimir G. Kolobov ◽  
Evgenii V. Aryshenskii ◽  
Yaroslav A. Erisov ◽  
Alexander Nam ◽  
Maksim S. Tepterev

The present study investigates the process of beverage can end forming from 5182 aluminum alloy. Stress-strain state during forming is analyzed using finite element method in PAM-Stamp 2G, and fracturing probability is evaluated based on V.L. Kolmogorov’s fracture criterion. It is established, that stress state does not provide the sufficient plasticity margin during ends forming. Blank material plasticity resource is depleted during preliminary and reverse drawing stages, defects accumulation during countersink forming is negligible. Minimum relative elongation value, responsible for fracture-free end forming, is 6% in the rolling direction.


2017 ◽  
Vol 899 ◽  
pp. 272-277
Author(s):  
Hugo Dutra Gomes ◽  
Maria Carolina dos Santos Freitas ◽  
Luciano Pessanha Moreira ◽  
Flavia de Paula Vitoretti ◽  
Jose Adilson de Castro

The present study is primarily engaged in the implementation of the incremental stamping process in a computerized numeric control This paper presents two different approaches to this forming process, an experimental and other numerical. Experimental used by the computer numerical control to perform the printing process and performs numerical simulations of the process using the finite element method. Some parameters are analyzed in both approaches, such as product geometry effects, tool geometry, tool speed, tool path, contact conditions and mechanical properties of the materials.


1982 ◽  
Vol 104 (3) ◽  
pp. 305-311 ◽  
Author(s):  
Ming-Ching Tang ◽  
Shiro Kobayashi

The metal-forming process of shell nosing at room temperature was analyzed by the finite-element method. The strain-rate effects on materials properties were included in the analysis. In cold nosing simulations, the nine-node quadrilateral elements with quadratic velocity distribution were used for the workpiece. The treatment of a moving boundary in the analysis of nosing is discussed and successfully implemented in the finite-element program. FEM simulations of 105-mm dia. shells of AISI 1018 steel and aluminum 2024 were performed and solutions were obtained in terms of load-displacement curves, thickness distribution, elongation, and strain distributions. Comparisons with experimental data show very good agreement.


2009 ◽  
Vol 16-19 ◽  
pp. 462-465
Author(s):  
Yong Fei Gu ◽  
Jun Ting Luo

The precision forming technology developed rapidly during passing two decades, however technologies of precision plastic forming the parts with deeper hole are far behind developed countries. The warm backward extrusion-ironing forming technology was presented for precision forming of non-circular hole joint in this paper. The forming process and parameter variable trend were simulated by finite element method, which the software MSC.Marc was applied. The forming die was designed and the forming experiment was finished. The products were deserved with good quality and performance. The feasibility of the forming technology is proved by experimental results and numerical simulation.


Author(s):  
К. П. Барахов

Thin-walled structures may contain defects as cracks and holes that are leftovers of the material the construction, is made of or they occur during the operation as a result of, for example, mechanical damage. The presence of holes in the plate causes a concentration of stresses at the boundary of the holes and ultimately leads to premature failure of the structural element. Repair of local damage of modern aircraft structures can be made by creating overlays that are glued to the main structure. The overlay takes on part of the load, unloading the damaged area. This method of repair provides tightness and aerodynamic efficiency to the structure. The calculation of the stress state of such glued structures is usually performed by using the finite element method. The classic models of the stress state of overlapped joints are one-dimensional. That is, the change of the stress state along only one coordinate is considered. At the same time, the connections of a rectangular form are also considered. The purpose of this work is to create a mathematical model of the stress state of circular axisymmetric adhesive joints and to build an appropriate analytical solution to the problem. It is assumed that the bending of the plates is absent; the deformation of the plates is even by thickness. The adhesive layer works only on the shift. The main plate and the overlay are considered isotropic. The solution is built on polar coordinates. The stress state of the connection depends only on the radial coordinate, i.e. one-dimensional. The solution is obtained in analytical form. This mathematical model is a generalization of the classical model of the adhesive connection of Volkersen to a circular or annular region and is considered for the first time. Boundary conditions are met exactly. The satisfaction of marginal conditions, as well as boundary conditions, leads to a system of linear equations with respect to the unknown coefficients of the obtained solutions. The model problem is solved and the numerical results are compared with the results of calculations performed by using the finite element method. It is shown that the proposed model has sufficient accuracy for engineering problems and can be used to solve problems of the design of aerospace structures.


Author(s):  
К.С. Бормотин ◽  
А. Вин

Рассматривается моделирование технологий обтяжки на прессе для изготовления обшивок двойной кривизны. Автоматизированное формообразование деталей требует разработки управляющей программы и электронной модели пуансона. Качество полученной детали будет зависеть от точности вычисленной и изготовленной формы оснастки, задающей упреждающую форму панели, и траектории деформирования листовой заготовки. При условии заданной оснастки ставится задача оптимального управления для поиска наилучшей траектории движения зажимов в оборудовании. Вводятся критерии оптимизации процессов деформирования, которые обеспечивают минимальную поврежденность и максимальные остаточные деформации. Вычисление критериев выполняется с помощью моделирования и анализа нелинейного деформирования панели с контактными ограничениями методом конечных элементов. Формулируется дискретная задача оптимального управления, которая решается методом динамического программирования. Алгоритмы численного метода, реализованные в пакете программ MSC.Marc, позволяют вычислить оптимальные параметры работы обтяжного пресса. Программная реализация алгоритма выполнена в последовательном и параллельном режимах. На основе вычислительных экспериментов показана эффективность параллельного расчета на кластере вычислительных машин. We analyze the stretchforming technology using a press to manufacture the doublecurvature shells. The automated shaping of parts requires the development of a control program and an electronic model of a punch. The quality of the part obtained depends on the accuracy of the calculated and manufactured tools that specify the anticipated shape of the panel and on the deformation path of the sheet. Under the condition of a given tooling, an optimal control problem is formulated to find the best trajectory of movement of the clamps in the equipment. Some criteria for deformation optimization processes are introduced to ensure a minimum damage and maximum residual deformations. The calculation of the criteria is performed with the aid of modeling and analyzing the panel nonlinear deformation with contact constraints by the finite element method. The problems of inelastic deformation are solved by the finite element method. A discrete optimal control problem is formulated and solved by the methods of dynamic programming. The algorithms are implemented using the MSC.Marc package and allow us to calculate the optimal parameters of the stretchforming press in serial and parallel modes. The obtained numerical results show the efficiency of parallel implementations on a cluster of computers.


2011 ◽  
Vol 337 ◽  
pp. 236-241 ◽  
Author(s):  
Xin Hua Huang ◽  
Hua Xiang ◽  
Xin Cun Zhuang ◽  
Zhen Zhao

Nowadays, the compound fine-blanking forming process is one of the most important processes to produce complicate multifunctional parts without subsequent machining. However, the big die-roll occurs in the sharp area is a common problem in this process. In this paper, the method with negative punch-die clearance was proposed to solve this problem by comparing three feasible plans. In addition, the influence on the process with different value of the negative punch-die clearance was studied by the finite element method (FEM). The results of this study verified that the process with suitable value of the negative punch-die clearance can result in significant decrease of the die-roll size. The relationship between the material flow near the region of die-roll and the punch-die clearance was also clarified.


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