# MOB250 Structural Modelling

## Course description for academic year 2020/2021

### Contents and structure

One of the most widely used methods for structural analysis is the finite element method. The method is implemented into most of the commonly used commercial codes for structural analysis. Such codes are used to design for instance buildings, ships, offshore and subsea installations, vehicles, airplanes and trains.The aim of the course is to provide basic understanding of the structural behaviour of the finite elements for analysis of various types of structures and establish skills towards the use of the method. Emphasis is placed on proper modelling, checking and results interpretation.

A compulsory project is part of the course. Both practical and theoretical challenges are relevant to study through the project.

### Learning Outcome

Knowledge:

• The concept of stress and strain
• The principle of virtual work
• Establishment of interpolation polynomials for various elements types
• Requirements for convergence and accuracy
• Use of natural coordinates and area coordinates for isoparametric elements
• Establishment of stiffness relationship for the C0 elements
• Numerical integration of stiffness matrix and load vector
• Calculation of stresses and strains in the element

Skills:

The candidate is able to:

• Use the virtual work to the formal derivation of the element stiffness relation
• Calculate the stiffness matrix and load vector for the 1D elements in detail
• Calculate the load vector for the plane elements
• Establish interpolation polynomials according to the zero-line method
• Transform displacements, stresses and strains
• Use generalized displacements
• Build up the structure stiffness relation from the elements' stiffness relations

Competence:

The candidate master:

• The general basis for the displacement-based finite element method
• The computational scheme in linear element calculations
• The awareness of poor accuracy of poor element geometry
• The necessary scepticism of results from finite element calculations.

None

### Recommended previous knowledge

Basic course in mechanics, mathematical analysis and vector algebra, extensive mathematical analysis and linear algebra or similar courses.

### Teaching methods

The course is organized as lectures, five compulsory homework assignments, a compulsory project which should be presented as a written report. The project is normally done in groups of 2-3 persons.

### Compulsory learning activities

Five home assignments. Valid mandatory assignments are valid in 3 semesters after approval.

### Assessment

4 hour written exam which counts 70% of the final grade. Project with written report which counts 30% of the final grade. Grading scale A-F, where F is not approved.

If there is a re-sit examination, the examination form may be changed from written to oral.

### Examination support material

All calculators are permitted.