Laser Forming of Varying Thickness Plate—Part II: Process Synthesis

2005 ◽  
Vol 128 (3) ◽  
pp. 642-650 ◽  
Author(s):  
Peng Cheng ◽  
Yajun Fan ◽  
Jie Zhang ◽  
Y. Lawrence Yao ◽  
David P. Mika ◽  
...  
Keyword(s):  
Plane Strain ◽  
Process Design ◽  
Laser Scanning ◽  
Plate Thickness ◽  
Laser Forming ◽  
Forming Process ◽  
Element Analysis ◽  
Varying Thickness ◽  
Bending Strain ◽  
Finite Element Analysis Simulation

Laser forming (LF) is a non-traditional forming process that does not require hard tooling or external forces and, hence, may dramatically increase process flexibility and reduce the cost of forming. While extensive progress has been made in analyzing and predicting the deformation given a set of process parameters, few attempts have been made to determine the laser scanning paths and laser heat conditions given a desired shape. This paper presents a strain-based strategy for laser forming process design for thin plates with varying thickness, which is utilized in determining the scanning paths and the proper heating conditions. For varying thickness plates, both the in-plane membrane strain and the bending strain need to be accounted for in process design. Compared with uniform thickness plate, the required bending strain varies with not only the shape curvature but also with the plate thickness. The scanning paths are determined by considering the different weight of bending strain and in-plane strain. A thickness-dependent database is established by LF finite element analysis simulation, and the heating conditions are determined by matching the ratio of bending strain to in-plane strain between the required values and the laser forming values found in the database. The approach is validated by numerical simulation and experiments using several typical shapes.

Process Design of Laser Forming for Three-Dimensional Thin Plates

2004 ◽  
Vol 126 (2) ◽  
pp. 217-225 ◽  
Author(s):  
Jin Cheng ◽  
Y. Lawrence Yao
Keyword(s):  
Process Design ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Thin Plates ◽  
Laser Forming ◽  
Heat Condition ◽  
Bending Strain ◽  
Doubly Curved ◽  
Made In

Extensive efforts have been made in analyzing and predicting laser forming processes of sheet metal. Process design, on the other hand, is concerned with determination of laser scanning paths and laser heat condition given a desired shape. This paper presents an approach for process design of laser forming of thin plates with doubly curved shapes. The important feature of this method is that it first calculates the strain field required to form the shape. Scanning paths are decided based on the concept of in-plane strain, bending strain, principal minimal strain and temperature gradient mechanism of laser forming. Heating condition is determined by a lumped method. Effectiveness of the approach is numerically and experimentally validated through two different doubly curved shapes.

Sheet Metal Forming Process Design Rules Development

2011 ◽  
Vol 473 ◽  
pp. 765-772
Author(s):  
Antonio del Prete ◽  
Gabriele Papadia ◽  
Teresa Primo
Keyword(s):  
Process Design ◽  
Process Variable ◽  
Complex Problem ◽  
Industrial Test ◽  
Thickness Ratio ◽  
Die Design ◽  
Design Development ◽  
Forming Process ◽  
Element Analysis ◽  
Constitutive Material

Finite element analysis (FEA) is a powerful tool to evaluate the formability of stamping parts during process and die design development procedures. However, in order to achieve good product quality and process reliability, FEA application has to be performed many times exploring different process parameters combinations. Meanwhile, it is very difficult to perform an exhaustive process design definition when many parameters play a fundamental role to define such a complex problem. So, under the needs of reduction in: design time, development cost and parts weight, there is an urgent need to develop and apply more efficient methods in order to improve the current design procedures. For a generic component it is clear how its shape, among several parameters, has a direct influence on its feasibility. Starting from this assumption, the authors have developed a new approach grouping components upon their shapes analyzing component formability within a given “component family”. Nowadays, it exists only a process designer “sensitivity” that produces a ranking upon shape/feasibility ratio. Having as reference industrial test cases, the authors have defined appropriate shape parameters in order to have dimensionless coefficients representative for the given geometries. In particular, the components have been classified using a parameters set defining similarity families: related to geometrical aspects and to constitutive material. From the geometrical point of view the following parameters have been defined: family name, shape factor, punch radius-thickness ratio, die radius-thickness ratio, while for the constitutive material a code has been defined. FEA has been extensively used in order to: define, investigate and validate each shape parameter with a proper comparison to the macro feasibility of the chosen component geometry. The feasibility configuration definition, for a given shape, has been made through an appropriate study of the influence of each process variable on the properly process performances.

Laser Forming of Varying Thickness Plate—Part I: Process Analysis

2005 ◽  
Vol 128 (3) ◽  
pp. 634-641 ◽  
Author(s):  
Peng Cheng ◽  
Yajun Fan ◽  
Jie Zhang ◽  
Y. Lawrence Yao ◽  
David P. Mika ◽  
...  
Keyword(s):  
Process Analysis ◽  
Scanning Speed ◽  
Spot Size ◽  
Laser Forming ◽  
Thickness Variation ◽  
Complex Structures ◽  
Forming Process ◽  
Forming Mechanism ◽  
Varying Thickness ◽  
Wide Range

High-intensity laser beams can be used to heat and bend metal plates, but the mechanisms of the laser forming (LF) process are not well understood or precisely controllable. The objective of the National Institute of Standards and Technology sponsored project “Laser Forming of Complex Structures” is to develop technologies for a controllable, repeatable laser forming process that shapes and reshapes a wide range of complex structures such as compressor airfoils that are complex 3D geometries with large thickness variation. In order to apply laser forming to complex 3D geometries, the process analysis and process synthesis (design process parameters such as scanning paths and heating conditions for a desired shape) of LF of varying thickness plate are conducted in this paper. In this study, experimental, numerical, and analytical methods are used to investigate the bending mechanism and parametric effects on the deformation characteristics of varying thickness plates. A transition of the laser forming mechanism was found to occur along the scanning path when the thickness varies. The effect of scanning speed, beam spot size, and multiple scanning on the degree of bending was investigated. The proposed analytical model can predict the bending angle and angle variations for laser forming of varying thickness plate.

Experimental Investigations and Automatic Numerical Optimization of a Bulk Metal Forming Process to Avoid Forging Folds

2015 ◽  
Vol 651-653 ◽  
pp. 305-310
Author(s):  
Bernd Arno Behrens ◽  
Sonda Moakhar Bouguecha ◽  
Milan Vucetic ◽  
Anas Bouguecha ◽  
Mohammad Kazhai
Keyword(s):  
Process Parameters ◽  
Process Design ◽  
Numerical Optimization ◽  
Experimental Investigations ◽  
Forming Process ◽  
Element Analysis ◽  
Complex Processes ◽  
Metal Forming Process ◽  
Fold Formation ◽  
Indispensable Tool

The detection of process failures in earlier design stages is essential for preventing high additional costs and a loss of time. Here, the finite element analysis (FEA) is an inherent part of the process design. This work represents numerical and experimental investigations, which were carried out in order to identify factors that influence the fold formation in an upsetting process of hollow parts, i.e. different forging velocities, different materials or the friction. The experimental results were compared with the numerical simulations. Based on these investigations, an automatic optimization model was created, which is the focus of this work. It allows varying and optimizing the experimentally determined process parameters, influencing the fold formation, automatically with the aim to produce a workpiece free of folds. For this purpose the commercial Software-System Forge (Transvalor) was used. The results of this work provide basic information for the development of complex processes. It can be shown that the automatic numerical optimization is an indispensable tool for the process design. It helps determining optimal process parameters individually and avoiding extensive trial and error investigations and hence a loss of time and costs.

scholarly journals Numerical Analysis of Fire Water Storage Tank under Seismic Loading

2021 ◽  
Vol 850 (1) ◽  
pp. 012019
Author(s):  
R Nishanth ◽  
D Kishok Rai ◽  
Hemkar Sharma ◽  
Rivington Kingston ◽  
Davidson Jebaseelan ◽  
...  
Keyword(s):  
Finite Element ◽  
Storage Tank ◽  
Hoop Stress ◽  
Plate Thickness ◽  
Water Storage ◽  
Bottom Plate ◽  
Element Analysis ◽  
Water Storage Tank ◽  
Finite Element Analysis Simulation ◽  
Shell Plate

Abstract Maintenance and continuously monitoring the condition of above ground storage tanks are significant when the tanks are placed in service. The American Petroleum Institution (API) 653 and other international codes provides the minimum requirements for inspection & maintaining the integrity of tanks during its service. The tank settlement is one of the major threats for tank’s integrity. In this paper, a storage tank is assessed for uniform settlement under various loading condition such as seismic, dead load, static load, corrosion loss of shell plate etc. In the present study, a finite element model is designed with uniform settlement condition and study of its governing hoop stress at shell plate has been carried out under different loading conditions. A fire water storage tank (constructed with IS 2060 GR. B material) and different seismic zones in India are taken for this study. The finite element analysis simulation shows that increase of hoop stress in the bottom shell course due to uniform settlement, the decrease in plate thickness and with different seismic active regions. Moreover, the maximum stresses have been observed at shell bottom course (close to bottom plate).

Modelling and Analysis of Extrusion Die and Bolt Ejector Pin

2014 ◽  
Vol 591 ◽  
pp. 137-141
Author(s):  
B. Vijaya Ramnath ◽  
Vishal Chandrasekhar ◽  
S. Pithchai Pandian ◽  
R. Sundarrajan ◽  
A. Santhosh Shankar ◽  
...  
Keyword(s):  
Process Design ◽  
Early Stage ◽  
Load Condition ◽  
Product Formation ◽  
Cad Tools ◽  
Element Analysis ◽  
Extrusion Die ◽  
Finite Element Analysis Simulation ◽  
Recent Developments ◽  
Product And Process

The computer aided tools and recent developments of engineering, emphasizes the importance of bringing manufacturing process into early stage for product and process design. The implied significance is that it becomes vital to reduce cost of product by extensive use of CAD tools for product formation without actually building the product. In this paper, CAD tools are used to design an extrusion die for bolt ejector pin. In this paper, the extrusion die used to produce the pin is modeled using Pro-E, a CAD tool. Then, the die is analyzed for the maximum extrusion load condition using ANSYS software, a Finite Element Analysis simulation (FEA) tool. The simulation results are compared with yield stress of material. After the die has been designed, the pin was extruded using the die. In order to evaluate the strength of extruded pin, the pin was also modeled and analyzed using ANSYS tool where it was found to be safe for its maximum ejection load condition.Keywords:Extrusiondiedesign,ejectorpin,Computeraidedmodelling(CAD),FiniteElementAnalysis(FEA).

Experimental and 3D Finite Element Studies of CW Laser Forming of Thin Stainless Steel Sheets

2000 ◽  
Vol 123 (1) ◽  
pp. 66-73 ◽  
Author(s):  
Guofei Chen ◽  
Xianfan Xu
Keyword(s):  
Finite Element ◽  
Stainless Steel ◽  
Laser Scanning ◽  
Continuous Wave ◽  
Laser Forming ◽  
Beam Diameter ◽  
Element Analysis ◽  
Scanning Velocity ◽  
3D Finite Element ◽  
Steel Sheets

Laser forming as a springback-free and noncontact forming technique has been under active investigation over the last decade. Previous investigations are mainly focused on forming of large and thick workpieces using high power lasers, with less work on precision, micro-scale bending of small and thin sheets. In this work, a 4 W continuous wave argon ion laser is used as the energy source, and the laser beam is focused to a beam diameter of tens of micrometers to induce bending of thin stainless steel sheets. When the laser scanning velocity is above 8 mm/s, bending can be explained by the temperature gradient mechanism, while decreasing the scanning velocity leads to the buckling mechanism of bending. The bending angle is measured at various processing conditions. A fully 3D finite element analysis is performed to simulate the thermo-elasto-plastic deformation process during laser forming. Experimental measurements and computational results agree in trend, and reasons for the deviation are discussed.

Investigation of Effect of Phase Transformations on Mechanical Behavior of AISI 1010 Steel in Laser Forming

2005 ◽  
Vol 129 (1) ◽  
pp. 110-116 ◽  
Author(s):  
Yajun Fan ◽  
Zhishang Yang ◽  
Peng Cheng ◽  
Keith Egland ◽  
Lawrence Yao
Keyword(s):  
Phase Transformation ◽  
Phase Transformations ◽  
Volume Fraction ◽  
Constitutive Relationship ◽  
Laser Forming ◽  
Transformation Kinetic ◽  
Forming Process ◽  
Element Analysis ◽  
Relationship Of ◽  
Phase Transformation Kinetic

In laser forming, phase transformations in the heat affected zone take place under steep cooling rates and temperature gradients, and have a significant affect on the laser forming process and final mechanical properties of products. In this work, phase transformations during laser forming of AISI 1010 steel are experimentally and numerically investigated and the transient volume fraction of each available phase is calculated by coupling the thermal history from finite element analysis with a phase transformation kinetic model. Consequently, the flow stresses of material are obtained from the constitutive relationship of the phases, and the laser forming process is modeled considering the effect of work hardening, recrystallization and phase transformation. A series of carefully controlled experiments are also conducted to validate the theoretically predicted results.

PROCESS OPTIMIZATION AND SENSITIVITY INVESTIGATION IN LASER FORMING WITH FINITE ELEMENT ANALYSIS

2007 ◽  
Vol 04 (04) ◽  
pp. 653-670 ◽  
Author(s):  
H. C. JUNG ◽  
S. KRUMDIECK
Keyword(s):  
Thermal Conductivity ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Process Optimization ◽  
Material Properties ◽  
Coefficient Of Thermal Expansion ◽  
Laser Forming ◽  
Bend Angle ◽  
Forming Process ◽  
Element Analysis

Laser forming is a flexible sheet metal manufacturing technique capable of producing various shapes, without hard tools and external forces, by irradiation across the surface of the metal piece. A three-dimensional thermal-elasto-plastic (TEP) finite element model for a straight line laser forming process has been developed during the course of this study, which simulates bend angles and temperature distributions. Laser forming process optimization and material sensitivity are investigated. In order to seek the optimal process conditions to generate a desired bend angle in the multi-scan laser bending process, an optimization algorithm based on the approximation of objective function and state variables is integrated into the numerical model. An optimal set of process parameters such as laser power, scan speed, beam diameter and the number of scans are obtained with optimization procedure. In order to assess process sensitivity to material roperties, associations between bend angle and material properties are statistically determined using the Pearson product-moment correlation coefficient via Monte Carlo simulations, for which a large number of the finite element simulations are carried out. The material properties of interest include the coefficient of thermal expansion, thermal conductivity, specific heat, modulus of elasticity, and Poisson's ratio. Results show that the process optimization coupled with finite element analysis can be used to determine processing parameters, and that the material properties of primary importance are the coefficient of thermal expansion, thermal conductivity and specific heat.

Research on the Metal Forming Process of the Muffler Tube Using Finite Element Method

2008 ◽  
Vol 385-387 ◽  
pp. 841-844
Author(s):  
Kyu Taek Han ◽  
Yi Jiong Jin
Keyword(s):  
Finite Element ◽  
Process Design ◽  
Metal Forming ◽  
Forming Process ◽  
Element Analysis ◽  
Punch Radius ◽  
Metal Forming Process ◽  
Fracture Theory ◽  
Simulation Results ◽  
Fourth Component

A muffler is an important part used to reduce noise and to purify exhaust gas in cars and heavy equipments. Recently there has been a growing interest in the designing and manufacturing the muffler tube due to the strict environmental regulations. The technique of perforating on the muffler tube has been largely affected by the shear clearance. And considering the concentration of the force around the punch edge, it is essential to reduced it through the punch radius. In this research, finite element analysis has been carried out to predict optimal forming conditions of the muffler tube using DEFORMTM-3D. In analysis, using one-fourth component of the punch and die, metal forming process is simulated and Cockcroft-Latham ductile fracture theory is used. According to the simulation results, when the shear clearance is 0.04mm, the punch radius is 0.05mm and the value of plate holder force is 250KN, the relation of load-stroke for punch is optimized. Also the burr is minimized and optimal shear section is obtained. The simulation results are reflected to the forming process design for the muffler tube.

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