A Study of Hydroforming for Processing Composites

2000 ◽  
Author(s):  
Michael A. Zampaloni ◽  
Farhang Pourboghrat ◽  
Andre Benard
Keyword(s):  
Numerical Analysis ◽  
Thermal Effects ◽  
Fluid Pressure ◽  
Cost Savings ◽  
Internal Stresses ◽  
Composite Sheet ◽  
Forming Process ◽  
Part Geometry ◽  
Glass Fiber Reinforced ◽  
Sheet Stamping

Abstract The use of hydroforming to shape complex composite parts is proposed in this work. Hydroforming is expected to greatly increase the formability of composite sheet by the use of a controllable heated, pressurized fluid. Hydroforming, in comparison with sheet stamping, is a more economical manufacturing process, since it does not require the use of a female die. The pressurized fluid acts as a support for the composite sheet throughout the forming process. A numerical analysis has been performed on this process in order to develop a method of predicting the final part geometry. The numerical analysis takes into account the pressurized fluid, the thermal effects, and the clamping mechanism used to hold the material in place as the part is formed. Numerical results show that using hydroforming for manufacturing glass fiber reinforced polypropylene composite material significantly reduces the strain, especially within the cup region of the hemispherical part. The fluid pressure also has an effect on the internal stresses of the part by allowing deeper draws before rupture. The experimentation, coupled with the prediction of the finite element modeling, indicates that the hydroforming of composite materials is a viable processing method that deserves more attention based on the significant advantages it provides in cost savings and part production accuracy.

Analysis of Single- and Two-Phase Flows in Turbopump Inducers

1967 ◽  
Vol 89 (4) ◽  
pp. 577-586 ◽  
Author(s):  
P. Cooper
Keyword(s):  
Equation Of State ◽  
Flow Field ◽  
Thermal Effects ◽  
Single Phase ◽  
Fluid Pressure ◽  
Three Dimensional ◽  
Pressure Rise ◽  
Recent Theory ◽  
Two Phase ◽  
Overall Efficiency

A model is developed for analytically determining pump inducer performance in both the single-phase and cavitating flow regimes. An equation of state for vaporizing flow is used in an approximate, three-dimensional analysis of the flow field. The method accounts for losses and yields internal distributions of fluid pressure, velocity, and density together with the resulting overall efficiency and pressure rise. The results of calculated performance of two sample inducers are presented. Comparison with recent theory for fluid thermal effects on suction head requirements is made with the aid of a resulting dimensionless vaporization parameter.

Wrinkling Prediction and Optimization of Sheet Metal Forming Process by Numerical Simulation

2015 ◽  
Vol 818 ◽  
pp. 252-255 ◽  
Author(s):  
Ján Slota ◽  
Marek Šiser
Keyword(s):  
Numerical Simulation ◽  
Material Model ◽  
Mechanical Tests ◽  
Simulation Software ◽  
Forming Process ◽  
Part Geometry ◽  
Nominal Thickness ◽  
430 Stainless Steel ◽  
Metal Forming Process ◽  
Aisi 430

The paper deals with optimization of forming process for AISI 430 stainless steel with nominal thickness 0.4 mm. During forming of sidewall for washing machine drum, some wrinkles remain at the end of forming process in some places. This problem was solved by optimization the geometry of the drawpiece using numerical simulation. During optimization a series of modifications of the part geometry to absolute elimination of wrinkling was performed. On the basis of mechanical tests, the material model was created and imported into the material database of Autoform simulation software.

Effects of Tool Deflection in Accumulated Double-Sided Incremental Forming Regarding Part Geometry

2016 ◽  
Author(s):  
Huaqing Ren ◽  
Newell Moser ◽  
Zixuan Zhang ◽  
Kornel F. Ehmann ◽  
Jian Cao
Keyword(s):  
Sheet Metal ◽  
Relative Position ◽  
Capital Investment ◽  
Incremental Forming ◽  
Position Angle ◽  
Tool Deflection ◽  
Geometric Accuracy ◽  
Localized Deformation ◽  
Forming Process ◽  
Part Geometry

Incremental forming is a flexible dieless forming process. In incremental forming, the metal sheet is clamped around its periphery. One or multiple generic stylus-type tools move along a predefined toolpath, incrementally deforming the sheet metal into a final, freeform shape. Compared with the traditional sheet metal forming process, the incremental forming process is more flexible, energy efficient and cost effective due to lower capital investment related to tooling. However, maintaining tight geometric tolerances in incremental formed parts can be a challenge. Specifically, undesired global bending is usually induced near the region between the tools and fixture resulting in a compromise in geometric accuracy. To address this issue, Accumulated Double-Sided Incremental Forming (ADSIF) is proposed, which utilizes two tools on both sides of the metal to better achieve localized deformation while simultaneously constraining global bending outside the forming area. Moreover, in ADSIF, the two tools are moving from inward to outward, and thus the tools are always forming virgin material and so as to limit forces on the already-formed part. Thus, ADSIF has a higher potential to achieve the desired geometry. Nevertheless, tool deflection due to machine compliance is still an issue that can have a considerable effect on geometric accuracy. In this work, the effect of tool deflection related to part geometry is studied for the ADSIF process. The nature of using two tools, rather than one, in ADSIF inherently implies that relative tool position is a critical process parameter. It is the region near these two tools where local squeezing and bending of the sheet occurs, the primary modes of deformation found in ADSIF. The change of relative tool positions (i.e., tool gap and relative position angle) are studied in detail by first developing an analytical model. It is concluded that the tool gap will be enlarged under the influence of tool compliance while the relative position angle is less affected. Additionally, a finite element simulation capable of modeling tool deflection is established. The comparison between the simulation results using rigid tools and deformable ones clearly demonstrated the significant influence of tool compliance on part geometry. Lastly, an axisymmetric part with varying wall angles was formed, and it was confirmed that ADSIF demonstrates improved geometry accuracy compared with conventional Double-Sided Incremental Forming.

Advanced In-Process Control System for Sheet Stamping and Tube Hydroforming Processes

2014 ◽  
Vol 622-623 ◽  
pp. 3-14 ◽  
Author(s):  
Kenichi Manabe
Keyword(s):  
Process Control ◽  
Metal Forming ◽  
Tube Hydroforming ◽  
Essential Element ◽  
Forming Limit ◽  
Forming Process ◽  
Intelligent Technique ◽  
Sheet Stamping ◽  
Adaptive Process Control ◽  
Metal Forming Process

A sophisticated servo press with the digital control has been developed and attracted attention in recent years. By utilizing its high function in-process, servo presses have a potential to enhance the forming limit and to improve quality and accuracy of product not only in sheet stamping but also in tube hydroforming processes. On the other hand, in-process control and adaptive process control technologies in metal forming processes using intelligent technique and soft computing have been investigated and developed previously. Nowadays we are in a good environment to realize further advanced adaptive in-process control in metal forming process. To further advance this technology, sensing system is essential element and it should be applied to feedback control optimally in their forming operation. This paper describes the current situation on advanced intelligent process control technology for sheet stamping and tube hydroforming processes on the basis of the research results by the author.

The Electric Arc Spray Manufacture of Rapid Production Tooling: A Case Study

1998 ◽  
Author(s):  
A.P. Newbery ◽  
P.S. Grant ◽  
R.M. Jordan ◽  
A.D. Roche ◽  
T.C. Carr
Keyword(s):  
Injection Moulding ◽  
Low Cost ◽  
Spray Forming ◽  
Electric Arc ◽  
Internal Stresses ◽  
Forming Process ◽  
Polymer Injection ◽  
Spray Process ◽  
Arc Spray ◽  
The U.S

Abstract The manufacture of tooling using the electric arc spray process to spray steel directly onto a master pattern offers substantial reductions in the lead times required to make complex tooling for polymer injection moulding and other applications. The process of spray forming is fast, efficient, and low cost, and has been shown to be dimensionally accurate with proper control over the residual stresses that develop during spraying. Poor dimensional control because of high internal stresses in thick arc sprayed steel coatings is well known, but these problems can be avoided by the use of correct spraying conditions. This paper describes the STD SPRAYFORM process for the manufacture of tooling for the polymer injection moulding of a component for a leading company in the U.S. The steps in the spray forming process, both before and after spraying, are described. The spray forming route competed directly with a traditional method for toolmaking and considerably reduced the lead time from order to completion. The tooling produced by spray forming has been operating commercially in production in the U.S. and has to date produced in the region of half a million parts without appreciable wear. The incorporation of contoured cooling channels during spraying has enabled plastic injection moulding cycle times to be decreased by 15%.

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