An investigation on the bending and curl-forming process of leads in integrated circuit packaging by the finite element method

2006 ◽  
Vol 41 (3) ◽  
pp. 205-219 ◽  
Author(s):  
Z-C Lin ◽  
C-C Chen
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.


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.


2012 ◽  
Vol 498 ◽  
pp. 183-188 ◽  
Author(s):  
Yong Yi Li ◽  
Sheng Dun Zhao

This paper firstly introduces the principle and characteristic of traditional extrusion tapping of internal thread, elaborates the material flow law during tapping process. Then puts forward a novel process of vibration-assisted extrusion tapping of internal thread, explains the effect mechanism of vibration during extrusion tapping of internal thread. Finally, with the finite element method (FEM), the simplified model of extrusion tapping are built, and the simulation of thread forming process of traditional extrusion tapping of internal thread are conducted, furthermore, the characteristic and influencing law of different vibration parameters (include vibration frequency, amplitude and direction) of vibration-assisted extrusion tapping of internal thread are studied, and some practical results are obtained. The simulation results show that applying vibration to extrusion tapping of internal thread can reduce tapping torque and improve thread forming quality, the reasonable selection of vibration parameters are very crucial to this novel process.


2014 ◽  
Vol 607 ◽  
pp. 112-117
Author(s):  
Khemajit Sena ◽  
Surasith Piyasin

This study aims to find a solution to improve the formability in a deep drawing process. For this purpose drawbeads were used to avoid wrinkles and ruptures. The finite element method was applied to simulate the 3D metal forming process using a die and drawbead. The drawbead amount, position, size and form were studied for their affects on the formability. 3 drawbead patterns with 3 different heights were examined. The simulation was performed for each drawbead pattern and each drawbead geometrical parameter and the failure elements were counted. The best pattern chosen was the pattern that resulted in the least failure elements.


Tribologia ◽  
2017 ◽  
pp. 29-36 ◽  
Author(s):  
Klaudiusz LENIK ◽  
Sylwester KORGA ◽  
Elżbieta KALINOWSKA-OZGOWICZ

This article presents the results of measurements on friction forces carried out in the model forming process (MFP). The description of this process takes into consideration the presence of plastic strain at the interface between the test specimen and tool due to the material flow. The experimental forming process was performer with a laboratory unit constructed and manufactured at the Fundamentals of Technology Faculty of the Lublin University of Technology [L. 1, 2]. This unit was used to carry out the measurements on friction force Turing model forming of shaped test specimens at a pressure of 0 to 100kN acting on a continuous basis during the research process. The results of experimental measurements of friction forces were compared to those of numerical calculations obtained with the finite element method (FEM). Experimental results of friction for ces were compared with the results obtained using the model forming process (MFP). In order to document the effects of plastic strain in the structure of shaped test specimens subjected to experimental model forming, metallographic examinations were carried out using a light microscope. Structure observations were conducted in a bright field and polarised light with a magnification of up to 2000x.


Sign in / Sign up

Export Citation Format

Share Document