Modern Hydroforming Technology

Contents
1 Introduction
1.1 Types and Characteristics of Hydroforming Technology
1.1.1 Definition and Types of Hydroforming
1.1.2 Technological Characteristics of Tube Hydroforming
1.1.3 Characteristics of Sheet Hydroforming Technology
1.1.4 Characteristics of Shell Hydroforming Technology
1.2 Overview of Hydroforming Technology
1.2.1 Overview of Tube Hydroforming Technology
1.2.2 Overview of Sheet Hydroforming Technology
1.2.3 Overview of Shell Hydroforming Technology
1.3 Development and Perspective of Hydroforming Technology
1.3.1 Development and Perspective of Tube Hydroforming
1.3.2 Development Direction and Perspective of Sheet Hydroforming
1.4 Recent Developments of Hydroforming
1.4.1 Recent Developments of Tube Hydroforming
1.4.2 Recent Developments of Sheet Hydroforming
1.4.3 Recent Developments of Shell Hydroforming
2 Hydroforming of Variable Diameter Tubular Parts
2.1 Process Stages and Application Fields
2.1.1 Process Stages
2.1.2 Application Fields
2.2 Determination of Main Process Parameters
2.2.1 Initial Yielding Pressure
2.2.2 Splitting Pressure
2.2.3 Calibration Pressure
2.2.4 Axial Feeding Force
2.2.5 Clamping Force
2.2.6 Axial Feeding Length
2.3 Defects and Loading Path
2.3.1 Type of Defects
2.3.2 Process Window and Loading Path
2.3.3 Limit Expansion Ratio
2.3.4 Control and Use of Wrinkles
2.4 Thickness Distribution and Influencing Factors
2.4.1 Thickness Distribution
2.4.2 Thickness Dividing Circle
2.5 Tubes for Hydroforming
2.5.1 Material
2.5.2 Requirement of Tube Materials
2.5.3 Types and Specification of Tubes
2.5.4 Measurement of Mechanical Properties of Tubes
2.5.5 Testing Methods and Apparatus for Mechanical Properties of Anisotropic Tubes
2.6 Friction and Lubrication During Hydroforming
2.7 Hydroforming Process of Typical Variable Diameter Tubular Parts
2.7.1 Hydroforming of an Aluminum Alloy Variable Tubular Part
2.7.2 Hydroforming of a Low Carbon Steel Tubular Part
2.7.3 Hydroforming of a Ω-shaped Joint Part
2.7.4 Hydroforming of an Irregular Tubular Part with Double Cones
2.7.5 Hydroforming of a Long Waved Pipe
3 Hydroforming of Curved Parts with Irregular Cross-Sections
3.1 Process and Typical Cross-Sections
3.1.1 Process Description
3.1.2 Typical Cross-Sections
3.2 Tube Bending Processes
3.2.1 Common Bending Processes and Characteristics
3.2.2 Minimum Bending Radius of Tube
3.2.3 Cross-Section Distortion and Prevention Approaches
3.2.4 Calculation of the Bending Moment
3.2.5 Thickness Variation
3.2.6 Ultimate Diameter-Thickness Ratio of Tube Bending
3.3 Hydro-Bending Process of Tubes
3.3.1 Principle and Characteristics of Hydro-Bending
3.3.2 Tube Hydro-Bending Without End Constraint
3.3.3 Tube Hydro-Bending with End Constraint
3.4 Type of Defects
3.5 Thickness Distribution of a Square Cross-Section
3.5.1 Effect of Expansion Ratio on Thickness Distribution
3.5.2 Effect of Friction Coefficient on Thickness Distribution
3.5.3 Effect of Parting Surface on Thickness Distribution
3.5.4 Effect of Material Mechanical Properties on Thickness Distribution
3.6 Principle and Method for Reducing Calibration Pressure
3.6.1 Principle of Reducing Calibration Pressure by Concave Preformed Cross-Section
3.6.2 The Correlation Between the Tangential Pushing Force and the Concave Depth
3.6.3 Calculation of Calibration Pressure for Concave Preformed Cross-Section
3.6.4 Shape Optimization Design of Concave Preform
3.6.5 Hydro-Pressing Process for the Preform
3.7 Hydroforming of Typical Parts with Curved Axis
3.7.1 Hydroforming of the Engine Cradle
3.7.2 Hydroforming of an Instrument Panel Beam
3.7.3 Hydroforming of an Aluminum Alloy Tubular Part
3.7.4 Hydroforming of an Aluminum Alloy Subframe Tubular Part
3.7.5 Hydroforming of MPV Passenger Car Subframe
3.7.6 Hydroforming of a DP590 Trailing Arm
3.7.7 Hydroforming of Torsion Beam of a High Strength Steel (780 MPa)
3.7.8 Hydroforming of a Crash Box
4 Hydroforming of Multi-branch Tubular Parts
4.1 Classifications and Processes of Multi-branch Tubes
4.2 Defect and Limit Height of Branch
4.2.1 Typical Defects
4.2.2 Limit Height of Branch
4.3 Thickness Distribution of Hydroformed Three-Branch Tubular Parts
4.4 Multi-step Hydroforming of Three-Branch Tube of Aluminium Alloys
4.4.1 Geometry and Challenges
4.4.2 Simulations of Multi-step Hydroforming of Three-Branch Tubular Part
4.4.3 Experiment on Multi-step Forming of Three-Branch Tube
4.5 Hydroforming of Ultra-Thin Three-Branch Tube of Stainless Steel
4.5.1 Geometry and Challenges
4.5.2 Finite Element Simulations of Multi-step Forming of Three-Branch Ultra-Thin Three-Branch Tube
4.5.3 Experiment on Multi-step Forming of Three-Branch Ultra-Thin Tube
4.6 Hydroforming of a Three-Branch Thin-Walled Tube of Ni-Based Superalloys
4.6.1 The Geometry of Ni-Based Superalloy Three-Branch Tube and Forming Difficulties
4.6.2 Experimentation of Multi-step Forming of Ni-Based Superalloy Three-Branch Tube
5 Stress–Strain Analysis for Tube Hydroforming
5.1 The Stress–Strain States and the Yield Locus During Hydroforming of Tubes
5.1.1 Initial Filling Stage
5.1.2 Forming Stage
5.1.3 Calibration Stage
5.2 The Stress–Strain States During Hydroforming of Curved Tubes and Three-Branch Tubes
5.2.1 The Stress–Strain States During Hydroforming of Curved Tubes
5.2.2 The Stress–Strain States During Hydroforming of Y-shaped Tubes
5.3 The Stress Locus of Tube Hydroforming
5.4 Stress-State of Corner Zone and Splitting Mechanism
5.4.1 Stress Analysis of Corner Zone
5.4.2 Mechanism of Splitting at the Corner Zone
6 Equipment and Tooling of Hydroforming
6.1 Construction and Functions of Hydroforming Equipment
6.1.1 Construction of Hydroforming Equipment
6.1.2 Sub-Systems of Hydroforming Equipment
6.2 Parameters of Hydroforming Equipment
6.2.1 Definitions of Main Parameters
6.2.2 Determination of Main Parameters
6.2.3 Recommendations of Standard and Parameters of Hydroforming Equipment
6.3 Typical Structures and Characteristics of the Die-Clamping Press
6.3.1 The Long-Stroke Die-Clamping Press
6.3.2 The Short-Stroke Die-Clamping Press
6.4 Large-Scale Hydroforming Equipment
6.4.1 Servo-Control of Ultra-High Pressure and Multi-axial Displacement
6.4.2 Computer Numerical Control System and Control Software
6.4.3 Series of Hydroforming Equipment Developed by HIT
6.4.4 The Layout of Hydroforming Production Line
6.5 Tooling of Hydroforming
6.5.1 The Structure and Material of Forming Dies
6.5.2 Effects of Thickness of Die Sidewall and Bottom Plate
7 Sheet Hydroforming Process
7.1 Procedure and Characteristics of Process
7.1.1 Forming Procedure
7.1.2 Characteristics of Sheet Hydroforming
7.1.3 Application Fields of Sheet Hydroforming
7.2 The Calculation of Main Process Parameters
7.2.1 The Critical Pressure of Liquid Cavity
7.2.2 The Forming Force
7.2.3 Blankholding Force
7.3 The Limit Drawing Ratio and Type of Defects
7.3.1 The Limit Drawing Ratio
7.3.2 The Type of Defects
7.3.3 The Stresses During Sheet Hydroforming Defects
7.4 Dimensional Accuracy and Thickness Distribution of Hydroformed Parts
7.4.1 Dimensional Accuracy
7.4.2 The Thickness Distribution
7.4.3 Springback Variation
7.5 The Equipment and Tooling of Sheet Hydroforming
7.5.1 The Construction of Sheet Hydroforming Equipment
7.5.2 The Characteristics and Main Parameters of Sheet Hydroforming Equipment
7.5.3 The Structure and Materials of Die-Sets
7.6 The Sheet Hydroforming with Radial Pressure
7.6.1 Process Procedure
7.6.2 Effect of Radial Pressure on the Forming Limit
7.6.3 Effect of Radial Pressure on the Thickness Distribution
7.7 The Sheet Hydroforming with Pre-bulging
7.7.1 Process Procedure
7.7.2 Thickness Distribution of Sheet Hydroforming with Pre-bulging
7.7.3 The Strengthening of Sheet Hydroforming with Pre-bulging
7.8 The Sheet Hydroforming of Typical Parts
7.8.1 Parabolic Cross-Section Shaped Parts
7.8.2 Box-Shaped Panel with a Single Curvature
7.8.3 Box-Shaped Panel with Double Curvatures
7.8.4 The Hydroforming of 2219 Aluminium Alloy Sheet
8 Die-Less Hydroforming of Shells
8.1 Structure of Shells and Manufacturing Process
8.2 Die-Less Hydroforming for Spherical Vessels
8.2.1 Forming Principle and Advantages
8.2.2 Forming Pressure
8.2.3 Polyhedral Structure Before Hydroforming
8.3 Die-Less Hydroforming of Ellipsoidal Shells
8.3.1 Die-Less Hydroforming of Ellipsoidal Shell
8.3.2 Relationship Between Stress and Axial Length Ratio of an Ellipsoidal Shell
8.3.3 Hydroforming Pressure for Ellipsoidal Shells
8.3.4 Hydroforming Experiment of Ellipsoidal Shell
8.3.5 Deformation and Wrinkling Behavior in Hydroforming of Ellipsoidal Shell
8.4 Die-Less Hydroforming of Ellipsoidal Shells with Double Generating Lines
8.4.1 Principle of Hydroforming of Ellipsoidal Shell with Double Generating Lines
8.4.2 Structural Design of Ellipsoidal Shell with Double Generating Lines
8.4.3 Hydroforming Experiment of Ellipsoidal Shell with Double Generating Lines
8.4.4 Variation of Curvature Radius During Hydroforming of Ellipsoidal Shell with Double Generating Lines
8.4.5 Variation of Shell Volume During Hydroforming of Ellipsoidal Shell with Double Generating Lines
8.4.6 Variation of Stress During Hydroforming of Ellipsoidal Shell with Double Generating Lines
8.5 Die-Less Hydroforming of Prolate Ellipsoidal Shells with Double Generating Lines
8.5.1 Hydroforming Experiment of Prolate Ellipsoidal Shell with Double Generating Lines
8.5.2 Volume Variation of Prolate Ellipsoidal Shell with Double Generating Lines in Hydroforming
8.5.3 Thickness Variation of Prolate Ellipsoidal Shell with Double Generating Lines in Hydroforming
8.6 Die-Less Hydroforming of Toroidal Shells
8.6.1 Die-Less Hydroforming Process of Toroidal Shells
8.6.2 Stress Distribution and Forming Pressure of Toroidal Shells
8.6.3 Die-Less Hydroforming Experiment of Toroidal Shells
8.6.4 Analysis on Wrinkling During Toroidal Shell Forming
8.6.5 Effect of Initial Structures of Toroidal Shell on Hydroforming
References