Creep age forming investigation on aluminum alloy 2219 and related studies
File(s)
Author(s)
Yang, Haoliang
Type
Thesis
Abstract
By the middle of the 20th Century, traditional mechanical metal forming methods were
showing to be inadequate for producing components comprising of large high strength
aluminium alloy panels with complex curvatures, such as those used in modern aircraft and
aerospace metal structures. To deal with this problem, a new forming method was conceived
by Textron, which has proven to be very useful for forming components with these
shape characteristics and good mechanical properties. The method is called Creep Age
Forming (CAF).
The
research described in this thesis is a study of CAF of a 2219 aluminium alloy,
which is used for fabricating the isogrid structure for fuel tanks of launch vehicles. The main
aim of the research is to develop experimental and modelling tools
for CAF of AA2219 sheet
structures.
A series of creep-ageing tests and stress-relaxation tests have been conducted on
AA2219 at 175
°C . The age-hardening, creep deformation and stress relaxation behaviour of
AA2219 have been investigated. Based on the experimental investigation, a novel set of
physically based, unified creep constitutive equations has been established.
A
small scale CAF test rig was designed to validate the springback prediction from FE
simulation. The experimental result and simulation are in good agreement. Development of
FE procedures for simulating creep-ageing behaviour of the material and springback has been
performed to predict and assess the springback behaviour of metal sheet in typical forming
tools.
showing to be inadequate for producing components comprising of large high strength
aluminium alloy panels with complex curvatures, such as those used in modern aircraft and
aerospace metal structures. To deal with this problem, a new forming method was conceived
by Textron, which has proven to be very useful for forming components with these
shape characteristics and good mechanical properties. The method is called Creep Age
Forming (CAF).
The
research described in this thesis is a study of CAF of a 2219 aluminium alloy,
which is used for fabricating the isogrid structure for fuel tanks of launch vehicles. The main
aim of the research is to develop experimental and modelling tools
for CAF of AA2219 sheet
structures.
A series of creep-ageing tests and stress-relaxation tests have been conducted on
AA2219 at 175
°C . The age-hardening, creep deformation and stress relaxation behaviour of
AA2219 have been investigated. Based on the experimental investigation, a novel set of
physically based, unified creep constitutive equations has been established.
A
small scale CAF test rig was designed to validate the springback prediction from FE
simulation. The experimental result and simulation are in good agreement. Development of
FE procedures for simulating creep-ageing behaviour of the material and springback has been
performed to predict and assess the springback behaviour of metal sheet in typical forming
tools.
Version
Open Access
Date Issued
2013-06
Date Awarded
2013-07
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
Davies, Catrin
Dear, John
Publisher Department
Mechanical Engineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)