Course objectives:
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In all industries, non-metallic materials, most often polymers (thermoplastics, thermosets, elastomers, foams), are often used in addition to conventional metals. The stress-strain behaviour of these materials is significantly more complex than metal. The stress dependence on the strain is not linear, with the stiffness of the material depending on both temperature and time (deformation velocity, load history). Therefore, it is shown how the mechanical behaviour of individual types of non-metallic materials differs and what material models (constitutive equations) are used to describe their mechanical behaviour. Attention is focused on homogeneous isotropic materials. The subject of the course is also the identification of material parameters of the most frequently used material models, as these parameters cannot usually be obtained in any other way. Concrete examples (e.g., rubber seal or foam damper) show how to create their model in commercial finite-element systems.
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Requirements on student
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Credit requirements:
Preparation and submission of semestral work of adequate level.
Exam requirements:
Active knowledge of the lectured subject and the ability to apply the presented substance when modelling of non-metallic structural parts.
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Content
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1) Types of non-metallic materials used in structural design and their mechanical behaviour (comparison with metals).
2) Modelling with consideration of infinitesimal or finite strains.
3) Polynomial hyperelastic models for isotropic and low compressible materials.
4) Other hyperelastic models.
5) Fatigue and aging models of elastomers (rubbers).
6) Mechanical tests for identification of parameters of hyperelastic models.
7) Algorithms for identification of material parameters of hyperelastic models.
8) Basic concepts of viscoelasticity.
9) Linear viscoelastic models.
10) Nonlinear viscoelastic models.
11) Mechanical tests for identification of parameters of viscoelastic models.
12) Algorithms for identification of material parameters of viscoelastic models.
13) Examples of application of different material models in practice.
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Activities
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Fields of study
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Guarantors and lecturers
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Literature
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Time requirements
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All forms of study
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Activities
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Time requirements for activity [h]
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Contact hours
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52
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Graduate study programme term essay (40-50)
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20
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Preparation for an examination (30-60)
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30
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Total
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102
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Prerequisites
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Knowledge - students are expected to possess the following knowledge before the course commences to finish it successfully: |
know the basic concepts of elasticity and strength (stress, deformation, Hooke's law) |
describe the mechanical behavior of metals in standard tests |
be familiar with the basics of the finite element method |
be familiar with the basic operations of linear algebra |
know the basic methods of differential calculus and integration of basic functions |
Skills - students are expected to possess the following skills before the course commences to finish it successfully: |
create a simple computational model using a commercial finite element system (eg NX, Abaqus, MSC Marc) |
evaluate the tensile test of steel (calculate the modulus of elasticity) |
compare the agreement between two functions by the method of least squares |
Competences - students are expected to possess the following competences before the course commences to finish it successfully: |
N/A |
N/A |
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Learning outcomes
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Knowledge - knowledge resulting from the course: |
describe the mechanical behavior of various non-metallic materials |
recognize the need to use a hyperelastic or viscoelastic material model |
describe the necessary mechanical tests to identify the parameters of hyperelastic and viscoelastic models |
Skills - skills resulting from the course: |
justify the choice of material model |
identify material parameters on the basis of given experimental data |
to create a computational model of a non-metallic part using a commercial finite-element system |
Competences - competences resulting from the course: |
N/A |
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Assessment methods
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Knowledge - knowledge achieved by taking this course are verified by the following means: |
Combined exam |
Individual presentation at a seminar |
Skills demonstration during practicum |
Skills - skills achieved by taking this course are verified by the following means: |
Combined exam |
Individual presentation at a seminar |
Skills demonstration during practicum |
Competences - competence achieved by taking this course are verified by the following means: |
Combined exam |
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Teaching methods
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Knowledge - the following training methods are used to achieve the required knowledge: |
Interactive lecture |
Practicum |
One-to-One tutorial |
Self-study of literature |
Skills - the following training methods are used to achieve the required skills: |
Interactive lecture |
Practicum |
Individual study |
Laboratory work |
Competences - the following training methods are used to achieve the required competences: |
Lecture |
Practicum |
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