|
Development of testing equipment for measuring mechanical properties of cancellous bone
Jiroušek, Ondřej ; Jírová, Jitka ; Vavřík, Daniel
Development of experimental procedures used for evaluation of mechanical properties of cancellous bone using small samples of cylindrical shape. Both the compressive and tensile specimens are tested while for the strain measurement an optical method utilizing CCD camera of high resolution is used. The procedure is used to assess the relationship between the apparent density of the cancellous bone in Hounsfield units obtained from computer tomography scans and viscoelastic material properties used in finite element modeling of whole bones.
|
| |
|
Large deformation - large amount of unknown
Fiala, Zdeněk
Finite deformations are exposed from a viewpoint of differential geometry. From this perspective infinite dimensional Riemannian geometry of Riemannian metrics is emplyed to propose novel objective time derivative by means of covariant derivative.
|
| |
|
Experimental determination of stress-strain dependence of non-standard materials
Vavřík, Daniel ; Drdácký, Miloš
The subject of this work is experimental determination of mechanical properties for different types of animal hairs. Mortars reinforced by thin fibres have promising properties for application in cultural heritage protection. Theoretical research is based on mathematical modeling of composite materials with inorganic (brittle) matrix and differential types of reinforcement fibres - natural as well as man made polymeric fibres. For these models, knowledge of mechanical properties of the fibres is needed. Optical method developed especially from this purpose will be introduced in this paper.
|
| |
| |
|
TWO-PARAMETER DESCRIPTION OF CRACKS IN THE VICINITY OF INHOMOGENEITY
Seitl, Stanislav ; Knésl, Zdeněk
In case of two-parameter linear fracture mechanics a study of inhomogeneity influence on behaviour of short cracks is performed. The values of stress intensity factor (KI), T-stress and strain energy density (SED) are shown as a function of material constants of both components. The calculation of numerical values of mechanical parameters is accomplished by using finite element method ANSYS.
|
| |
|
Comparison of stability criteria of V-notched body under combined mode of loading
Klusák, Jan ; Knésl, Zdeněk
The stability criteria of V-notched bodies under combination of loading modes I and II are suggested and compared in the article. Methodology of stability criterion suggestion is based on analogy between behaviour of body with a crack and with a V-notch. Analytical approach to suggestion of stability criteria and methods of numerical estimation of magnitudes controlling stability of the concentrators are shown in the article. Corresponding evaluations are obtained from finite element method system ANSYS. Suggested criteria are mutually compared.
|