Metals Material Modelling: Creep

How is creep behaviour in metals simulated and used in practical engineering applications?
What are the potential difficulties and challenges in modelling creep problems using FE software?
What are the potential errors and limitations of the FE creep solutions?

This course gives you practical advice with a minimum of theory.

Metals Material Modelling: Creep

This eLearning course is aimed at engineers and designers who want to learn about how metal creep is modelled using FE software.

The course will cover creep theories and approximations that are widely used to analyse practical high-temperature engineering applications. Mathematical formulations and equations are intentionally kept to a minimum. Emphasis will be placed on how engineering design incorporates these theories and how the FE method models metal creep.

Difficulties encountered by both the FE user and the FE software in modelling creep will be highlighted using many examples to demonstrate creep behaviour and how to assess the accuracy of the FE solutions.

The pre-requisite for this course is a working knowledge of linear finite element theory and applications. No prior knowledge of creep theory is required. The course is independent of any FE software code.

 

Why an e-learning class?

Travel and training budgets are always tight! The e-Learning course has been developed to help you meet your training needs.

If your company has a group of engineers, or specific training requirements across any subjects, please contact us to discuss options.


Course Program

This is a three-week live web-based eLearning course with a total of 6 hours of tuition (presented as a two-hour session per week). Delegates will be provided with copies of all lecture slides including many self-test problems (with worked solutions).

Session 1

Introduction to Creep Behaviour

  • Creep behaviour in metals
  • Creep laws at high temperature
  • Time-dependency in creep
  • Creep laboratory tests
  • Plotting creep test data
  • Small specimen and impression creep tests

Review of Creep formulations

  • Creep under changing loads
  • Time-hardening vs. strain-hardening
  • Creep rupture life
  • Stress relaxation during Creep
  • Multi-axial 3D creep formulations

Self-test questions (optional homework)- Questions to reinforce the topics covered in the lectures

 

Session 2

Computational modelling of creep

  • Modelling nonlinear material behaviour
  • Modelling time-dependency
  • Explicit and implicit time marching techniques
  • FE creep algorithms

Solutions to self-test questions (Full solutions highlighting the key aspects)

Creep behaviour in Engineering design

  • Creep life estimation
  • Creep fracture and crack propagation
  • Creep-fatigue interaction
  • Creep in beams and thick cylinders

More Self-test questions (optional homework)

 

Session 3

Modelling Creep Using FE software

  • Difficulties encountered in modelling creep problems
  • User-defined complex creep laws
  • Modelling creep damage and rupture
  • Modelling Creep around cracks

Solutions to more self-test questions

FE Creep Examples

  • Constant-load creep example
  • Stress relaxation creep example
  • Variable-load creep example
  • Multi-axial pressurised cylinder creep example
  • Creep rupture and damage example

Summary of key points, tips and guidelines

 

Feedback from former e-Learning students:

"Super! Doesn't get better than this. Good idea to start having e-Learning courses."

R.P.

"I'm really happy not to pay a big fraction of my annual training budget to airlines and hotels. A BIG plus to e-learning."

V.G.

 

PSE

PSE Competencies addressed by this training course

IDCompetency
CTDkn1State Norton's Power Law and the Hyperbolic-Sine Law for secondary creep.
CTDkn2State the Time Hardening and Strain Hardening Laws, based on Norton s Power Law, for primary creep.
CTDkn3State how typical creep laws depend on temperature.
CTDkn4List the range of creep and time-dependent constitutive models available in any finite element used.
CTDkn5Identify the extent to which your application software allows modification of creep solution parameters.
CTDkn6State the basic definitions of stress relaxation and creep.
CTDco1Describe and illustrate a standard creep curve for steels, highlighting the steady state regime.
CTDco2Using the standard creep curve, describe the effects of (i) increasing stress level and (ii) removing the stress.
CTDco3 Describe different ways of presenting creep data.
CTDco4Explain the term Stress Redistribution in a structure subject to creep under load.
CTDco5Discuss the term Creep Rupture and illustrate how data related to this is commonly presented.
CTDco6Describe how a creep damage law and life fraction rule are used.
CTDco7Explain, in general terms, the creep solution process as typically implemented in finite element systems.
CTDco8Outline how the Creep Strain Tolerance and change in stress level during a time interval are used to control the accuracy of creep calculations.
CTDco9Contrast the creep solution procedure with the procedure commonly employed for plasticity.
CTDco10 Discuss the complexities arising from a multiaxial stress state and illustrate how these are normally handled.
CTDco11 Discuss the advantage and validity of using a stiffness matrix that doesn't vary during the creep solution.
CTDco12Discuss the theoretical solution for steady state creep stresses for a beam in bending.
CTDco13 Discuss the theoretical solution for steady state creep stresses for a thick cylinder under internal pressure.
CTDco14Explain why it is important to carefully consider the output required from a finite element system for this type of analysis.
CTDco17 Contrast Explicit and Implicit Creep Integration.
CTDco18 Discuss how the interaction of creep and fatigue is generally handled in design standards or Codes of Practice.
CTDco19 Describe why a creep analysis is necessary for relevant components in your organisation or sector.
CTDap1 Define creep constitutive data as appropriate.
CTDap2 Use FEA to obtain creep solutions for a range of typical components.
CTDap3Use facilities to enter user-defined creep constitutive laws as appropriate.
CTDap4Conduct effective creep analyses for stiffness and strength.
CTDap6Conduct effective creep - fatigue interaction studies.
CTDan1Analyse the results from time dependent analyses of typical pressure components and determine whether they satisfy relevant design standard or code of practice r...
CTDsy1Plan a series of simple benchmarks in support of a more complex creep or time dependent analysis.
CTDsy2Plan modelling strategies for time dependent problems.
CTDsy3 Prepare an analysis specification for a time dependent analysis, including modelling strategy, highlighting any assumptions relating to geometry, loads, boundary...
CTDev1Select appropriate idealisation(s) for components / structures, that are consistent with the objectives of the time dependent analyses.
CTDev4Select appropriate solution schemes for time dependent problems.

 

Three-Session Online Training Course

2 hours per session
PDH Credits - 6

Attend the live sessions, or view the recordings at your convenience.

Not Available to Attend this Time?

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Please click here to view the FAQ section, or if you need to contact NAFEMS about this course.

Engineering Board PDH Credits

*It is your individual responsibility to check whether these e-learning courses satisfy the criteria set-out by your state engineering board. NAFEMS does not guarantee that your individual board will accept these courses for PDH credit, but we believe that the courses comply with regulations in most US states (except Florida, North Carolina, Louisiana, and New York, where providors are required to be pre-approved)


Special Note(s):

Telephony surcharges may apply for attendees who are located outside of North America, South America and Europe. These surcharges are related to individuals who join the audio portion of the web-meeting by calling in to the provided toll/toll-free teleconferencing lines. We have made a VoIP option available so anyone attending the class can join using a headset (headphones) connected to the computer. There is no associated surcharge to utilize the VoIP option, and is actually encouraged to ensure NAFEMS is able to keep the e-Learning course fees as low as possible. Please send an email to the e-Learning coordinator (e-learning @ nafems.org ) to determine if these surcharges may apply to your specific case.

Just as with a live face-to-face training course, each registration only covers one person. If you plan to register a large group (10+), please send an email to e-learning @ nafems.org in advance for group discounts.

For NAFEMS cancellation and transfer policy, click here.