The Results Comparasion of Calculation Method and Computer Modeling of Double Curvature Sheet Shells in Stretch Forming Process

2016 ◽  
Vol 684 ◽  
pp. 21-28 ◽  
Author(s):  
V.A. Mikheev ◽  
S.V. Surudin
Keyword(s):  
Computer Simulation ◽  
Key Words ◽  
Calculation Method ◽  
Stretch Forming ◽  
Forming Process ◽  
Double Curvature ◽  
Formation Stage ◽  
Straight Line ◽  
The Press ◽  
Simulation Results

In this paper was conducted the dichotomous principle analysis, which based on the results comparability of calculation method and the computer simulation results of forming double curvature sheet shells using new scheme stretch forming and program PAM-stamp. The new scheme involves initially perform shaping the central part of the shell with the press jaws of the straight line. Then press clips installed on the contours, which corresponding with curves of stretch die end sections, and performed extension stretch forming up to a point. The results of the calculation method allows to compare the formation stage and extension stretch forming on the results of computer simulation and quickly find the practical applicability of the new scheme extension stretch forming on modern stretch forming press such as FEL. Key words: extension stretch forming process, double curvature shell, computer simulation results, calculation method, stretch forming press FEL.

scholarly journals The Effect of Swinging Ball Heads with Different Arrangements in Multi-Point Stretch-Forming Process

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 337 ◽  
Author(s):  
Jian Xing ◽  
Yan-yan Cheng ◽  
Zhuo Yi
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Sheet Metal ◽  
Strain Distribution ◽  
Finite Element Models ◽  
Stretch Forming ◽  
Forming Process ◽  
Forming Quality ◽  
Staggered Arrangement ◽  
Simulation Results

To improve the effect of multi-point stretch forming of sheet metal, it is proposed in this paper to replace a fixed ball head with a swinging ball head. According to the multi-point dies with different arrangements, this research establishes finite element models of the following stretch forming, i.e., fixed ball heads with conventional arrangement, swinging ball heads with conventional arrangement, swinging ball heads with declining staggered arrangement, and swinging ball heads with parallel staggered arrangement, and then numerical simulation is performed. The simulation results show that by replacing a fixed ball head with a swinging ball head, the surface indentation of the part formed was effectively suppressed, the stress and tension strain distribution of the part formed was improved, and the forming quality was improved; the thickness of the elastic pad was reduced, the springback was reduced and the forming accuracy was improved; and when the ball head was applied to a multi-point die with staggered arrangement, a better forming result was achieved, where the best forming result was achieved in combining the swinging ball heads with the multi-point die with a parallel staggered arrangement. Forming experiments were carried out, and the experimental results were consistent with the trend of numerical simulation results, which verified the correctness of the numerical simulation.

scholarly journals Method for Optimizing the Kinematic Scheme of Stretch-Forming Parts from Sheet Blanks

2021 ◽  
Vol 346 ◽  
pp. 01030
Author(s):  
Konstantin Bormotin ◽  
Anton Krivenok ◽  
Maria Pogartseva ◽  
Min Ko Hlaing
Keyword(s):  
Optimal Control ◽  
Optimal Control Problems ◽  
Optimization Criterion ◽  
Control Problems ◽  
Optimal Parameters ◽  
Kinematic Scheme ◽  
Stretch Forming ◽  
Forming Process ◽  
Residual Displacements ◽  
Simulation Results

The modeling of the stretch-forming process a sheet on a punch is considered. A numerical method has been developed for solving the optimal control problems of the stretch-forming process sheet blanks. The values of the residual displacements are considered as an optimization criterion. The algorithms implemented in CAE allow calculating the optimal parameters for the operation of the CNC stretch-forming press. The simulation results are compared with full-scale experiments on the shaping of sheet parts on a stretch-forming press T-600.

Spring-Back Evaluation of Stretch Bending Process Based on Chaboche Combined Isotropic-Kinematic Hardening Laws

2011 ◽  
Vol 204-210 ◽  
pp. 1745-1750 ◽  
Author(s):  
Jing Hu ◽  
Xiao Xing Li ◽  
Kwan Soo Chung ◽  
Rao Yao
Keyword(s):  
Kinematic Hardening ◽  
Spring Back ◽  
Stretch Forming ◽  
Forming Process ◽  
Hardening Law ◽  
Stretch Bending ◽  
User Subroutine ◽  
Bending Process ◽  
Chaboche Model ◽  
Simulation Results

We present a study on spring-back prediction in the stretching bending process using the Chaboche model combined isotropic-kinematic hardening law and Mises yielding criterion, and a material user subroutine (VUMAT, UMAT) program was developed base on the ABAQUS interface for the model. The effects of different hardening law on the spring-back in the stretch forming process was also analyzed and compared. The simulation results show that the combined isotropic-kinematic hardening law has the better spring-back prediction compared with the pure isotropic and kinematic hardening law in the stretch forming process, which is verified by the experimental results.

Numerical Analysis of the Multi-Point Stretch Forming Process of Aircraft Outer Skin Part

2010 ◽  
Vol 154-155 ◽  
pp. 1068-1072
Author(s):  
Shao Hui Wang ◽  
Zhong Yi Cai ◽  
Ming Zhe Li ◽  
Ying Wu Lan
Keyword(s):  
Numerical Simulation ◽  
Numerical Analysis ◽  
Flexible Manufacturing ◽  
Stretch Forming ◽  
Forming Process ◽  
Outer Skin ◽  
Free Length ◽  
Simulation Results ◽  
The Cost ◽  
Elastic Cushion

As a flexible manufacturing technique, Multi-point stretch forming (MPSF) is a suitable method for forming aircraft outer skin part. The traditional solid stretching die is replaced by the discrete multi-point die (MPSD), and the sheet metal is stretch-formed over the MPSD generated by serial adjusting mode or parallel adjusting mode. The MPSF can be used to form the parts of different shape and reduce the cost and leading time of stretching die fabrication for aircraft outer skin part. A series of numerical simulations on typical MPSF processes of aircraft outer skin part were carried out. The thickness of elastic cushion and free length are important factors to influence on the stretch forming results of stretch-formed parts. The numerical simulation results show that the thicker the elastic cushion is, the more valid the dimple will be suppressed .The longer the free length is, the easier the wrinkle will be brought.

Optimum Shape and Dies Design for New Thin Metal Gasket by Using Simulation Experiment

2014 ◽  
Vol 575 ◽  
pp. 271-275 ◽  
Author(s):  
Moch. Agus Choiron ◽  
Anindito Purnowidodo
Keyword(s):  
Computer Simulation ◽  
Optimal Design ◽  
Simulation Experiment ◽  
Design Stage ◽  
Optimum Shape ◽  
Virtual Design ◽  
Forming Process ◽  
Press Forming ◽  
Simulation Results ◽  
Corrugated Metal

In this study, new thin corrugated metal gasket will be developed by using simulation experiment. The optimal design and dies design for gasket manufacturing is determined by using computer simulation based on finite element analysis (FEA). In the design stage, the Taguchi method is used to predict optimal design of new thin corrugated metal gasket. The L9 orthogonal array was concerned to design experimental matrix for four factors with three levels. In the manufacturing stage, gasket product is simulated by using ANSYS 14.5 and experimental press forming process by using press hydraulic machine. From the result, the optimal design is the model with R = 3 mm, p = 6 mm, OH = 3 mm and h = 0.2 mm. Based on simulation results and experimental press forming product, it can be concluded that the virtual design from computer simulation results can be used for predicting the real product.

scholarly journals The Effect of Swinging Ball Heads with Different Arrangements in Multi-Point Stretch Forming Process

2019 ◽  
Author(s):  
Jian Xing ◽  
Yan-yan Cheng ◽  
Zhuo Yi
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Strain Distribution ◽  
Finite Element Models ◽  
Stretch Forming ◽  
Forming Process ◽  
Forming Quality ◽  
Staggered Arrangement ◽  
Simulation Results ◽  
Formed Part

To improve the effect of multi-point stretch forming of sheet metal, it is proposed in this paper to replace fixed ball head with swinging ball head. According to the multi-point dies with different arrangements, this research establishes the finite element models of the following stretch forming, i.e. fixed ball heads with conventional arrangement, swinging ball heads with conventional arrangement, swinging ball heads with declining staggered arrangement, and swinging ball heads with parallel staggered arrangement and then numerical simulation is performed. The simulation results show that by replacing fixed ball head with swinging ball head, the surface indentation of the formed part was effectively suppressed, the stress and tension strain distribution of the formed part was improved and the forming quality was improved; that the thickness of the elastic pad was reduced, the springback was reduced and the forming accuracy was improved; and that when the ball head was applied to multi-point die with staggered arrangement, better forming result was achieved, where the best forming result was achieved in combining the swinging ball heads with the multi-point die with parallel staggered arrangement. The forming experiments were carried out, and the experimental results were consistent with the trend of numerical simulation results, which verified the correctness of the numerical simulation.

scholarly journals APPLICATION OF ANTIFRICTION COATINGS TO REDUCE CONTACT FRICTION IN STRETCH-FORMING PROCESS OF DOUBLE CURVATURE SHELLS ON A DIES MADE OF ALUMINUM ALLOYS

2021 ◽  
Vol 23 (1) ◽  
pp. 41-47
Author(s):  
G.L. Rivin ◽  
◽  
E.G. Karpukhin ◽  
A.O. Koshkina ◽  
◽  
...  
Keyword(s):  
Aluminum Alloys ◽  
Coefficient Of Friction ◽  
Contact Friction ◽  
Technological Properties ◽  
Stretch Forming ◽  
Forming Process ◽  
Properties Of Coatings ◽  
Double Curvature ◽  
Antifriction Coatings ◽  
The Coefficient Of Friction

The article presents the results of research on antifriction coatings for use on die made of aluminum alloys. The expediency of using antifriction coatings to reduce friction when stretch-forming of double curvature shells is justified. To substantiate this, we performed numerical modeling of the skin-tight forming process in the «LS-dyna» CAE system. According to the results of modeling, the following relationship is observed: the lower the coefficient of friction, the more evenly distributed the thinning deformations over the thickness of the blank in stretch-forming. Test modes for determining the coefficient of friction on the MTU-01 friction machine and methods for obtaining other basic functional and technological properties of antifriction coatings are described. The antifriction and technological properties of coatings, such as the coefficient of friction, adhesion, wear resistance, conditional hardness, the time and temperature of polymerization of the coating are determined.

Influence of the Sheet Metal Anisotropy on Polythickness of the Skin after Stretch Forming

2017 ◽  
Vol 743 ◽  
pp. 207-211 ◽  
Author(s):  
Sergey Surudin ◽  
Yaroslav Erisov ◽  
Dmitrij Chernikov
Keyword(s):  
Mechanical Properties ◽  
Mathematical Model ◽  
Computer Simulation ◽  
Regression Analysis ◽  
Yield Strength ◽  
Software Package ◽  
Uniform Elongation ◽  
Optimal Combination ◽  
Stretch Forming ◽  
Forming Process

Computer simulation of the stretch forming process of the with different anisotropy of properties in the software package PAM-STAMP 2G was implemented in the work. The design of the multivariate experiment was made to analyze the effect of the anisotropy of the mechanical properties over the final polythickness of the skin after stretch forming. The regression analysis of the results was implemented after simulation, besides a mathematical model of polythickness dependence on the anisotropy of the properties was formulated. The optimal combination of Lankford coefficients, ultimate strength, yield strength and uniform elongation that minimizes polythickness of the finished skin was established.

SIMULATION OF SOFT START OF SYNCHRONOUS ELECTRIC DRIVES

2019 ◽  
Author(s):  
Shakhboz Dadabaev
Keyword(s):  
Computer Simulation ◽  
Electric Drive ◽  
Water Supply Systems ◽  
Factors Affecting ◽  
Electric Drives ◽  
Soft Start ◽  
Simulation Results ◽  
Pumping Units ◽  
Negative Factors ◽  
Supply Systems

The main negative factors affecting the starting modes of synchronous electric drives of pumping units of irrigation water supply systems were identified, computer simulation of direct and soft start of synchronous electric drive was made, the simulation results are shown in graphs and a brief conclusion was made on the study.

Transfers with a rendezvous lasting no more than one orbit between close near-circular coplanar orbits

2020 ◽  
pp. 82-93
Author(s):  
Aleksandr F. BRAGAZIN ◽  
Alexey V. USKOV
Keyword(s):  
Key Words ◽  
Relative Velocity ◽  
Free Parameter ◽  
Space Station ◽  
Characteristic Velocity ◽  
Orbital Station ◽  
Orbit Transfer ◽  
Simulation Results ◽  
The Moment ◽  
Phase Differences

Consideration has been given to orbit transfers involving spacecraft rendezvous which belong to a class of coplanar non-intersecting near-circular orbits of a spacecraft and a space station. The duration of the transfer is assumed to be limited by one orbit. The feasibility of a rendezvous using an optimal two-burn orbit-to-orbit transfer is studied. To determine a single free parameter of the transfer, i.e. the time of its start, ensuring a rendezvous at a given time or at a given velocity at the end of transfer, appropriate equations have been obtained To implement in the guidance algorithms optimal three-burn correction programs are proposed to achieve a rendezvous at a given time with a specified relative velocity at the moment of spacecraft contact. A range of phase differences at the start of maneuvering is determined, within which the characteristic velocity of the rendezvous is equal to the minimum characteristic velocity of the orbit-to-orbit transfer. The paper presents simulation results for “quick" rendezvous profiles that use the proposed programs. Key words: spacecraft, orbital station, “quick” rendezvous, orbit transfer, rendezvous program.

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