|
| |
|
|
Application of inverse FEM analysis for materials curve determination based on indentation test
Brumek, J. ; Strnadel, B. ; Dlouhý, Ivo
Study of instrumented indentation test is focused on prediction of the strain hardening behavior of the carbon steels. Indentation tests were applied on several steels samples. We proposed an improved technique to determine the plastic properties of material from the loaddisplacement curve from ball indentation test. The inverse finite element method was used for prediction of material properties. Results were found in good agreement with the data from conventional standard test. This non-destructive assessment of deformation behavior has good potential for the other materials.
|
|
|
Instrumented indentation test used for mechanical properties determination
Brumek, J. ; Strnadel, B. ; Dlouhý, Ivo
Focusing on the materials with non-linear stress-strain behavior an instrumented indentation study is presented. Indentation tests were applied on steel R7T. The observed data were analyzed and mechanical properties, such as yield stress, strain hardening exponent and elastic modulus were assessed. Experimental results of load-depth (P-h) test were compared with FEM solution. FEM analysis was applied on two-dimensional model described by elastic-plastic elements. Presented method of prediction in mechanical characteristics is useful to judge deformations of steel and other materials under contact stressing. Experimental results of P-h relation and additional FEM analysis of indentation test provide very helpful information of mechanical behaviors in contact of two bodies.
|
|
|
Mechanical properties evaluation by means of instrumented indentation test
Brumek, J. ; Strnadel, B. ; Dlouhý, Ivo
An instrumented indentation study focusing on the materials with non-linear stress-strain behavior is presented. Indentation tests were applied on steel R7T. The observed data were analyzed and mechanical properties, such as yield stress, strain hardening exponent and elastic modulus were assessed. Experimental results of load-indentation depth test were compared with FEM solution. FEM analysis was applied on two-dimensional model described by elastic-plastic elements. Presented approach to prediction of mechanical characteristics is useful for estimation of remanent lifre of steels and other materials by using indentation method.
|
|
|
Transgranular and intergranular failure competition as a manifestation of steel degradation
Dlouhý, Ivo ; Hadraba, Hynek ; Strnadel, B.
Main purpose of the work was to quantify causes and characteristics that control the intergranular fracture initiation and occurrence of this fracture micromechanism in competition with cleavage one. A CrNi steel of commercial quality and the same steel with increased content of impurity elements, Sn and Sb, was used. Step cooling treatment was applied in order to induce intergranular embrittlement and brittle fracture initiation in both steel melts. For fracture toughness determination standard bend specimen and pre-cracked Charpy type specimens both tested in three point bending were applied. Relation of cleavage fracture stress and critical stress for intergranular failure has been followed showing capability of this parameter for quantification of the transgranular/intergranular fracture. In order to characterise the quantitative morphological differences in fracture surfaces fractal analysis was applied.
|
guest ::
