Papers by Keyword: Three Point Bend Test

Abstract: This paper studies different modelling methodologies for a calculation of the three point bend test. Test samples are composed of a rubber matrix and either steel or textile cords reinforcement. Prior to the bending tests, all of the used materials including the matrix and the reinforcement were measured to find out their mechanical properties. Rubber materials were described using hyperelastic models. FEM software MSC Marc/Mentat is employed as a calculation tool and its various functionalities are utilized for a description of the test composite models. The main observed outcome is a dependence of the vertical force causing the test sample deformation on the amount of the deformation. Calculated results are compared to each other and to measurements. Then, all the modelling techniques are evaluated.

Abstract: In this work, the mechanical behavior on AISI 4140 with boride coating and hardened quenching-tempering was studies subsequently to boriding. The boriding is conducted at temperatures 1203 and 1233 K for 7 h, after that all samples at a temperature of 1143 K for 1 h and tempering 473 K were exposed for 1 h 30 minutes. The microstructural characterization was examined by scanning electron microscopy with saw-tooth morphology of boride coatings type Fe₂B. Three-point bend test was used to study the effect of hydrogen cathodic charging on the mechanical behavior of AISI 4140 with boride coatings, the results show a reduction of ductility and 58.17% of indices of embrittlement () and show a crack on the substrate due to interaction of hydrogen atom. Also, sample boride at 1203 K with hydrogen show a low decrease of the bending stress with respectively a sample boride without hydrogen and a decrease of the parameter () with 35.32% due to the formation of boride coatings.

Abstract: The aim of the paper is focused on the analysis of the mechanical properties of the concrete specimens with plasticizer at three point bending test by the signal analysis of the acoustic emission signal. The evaluations were compared the measurement and the results obtained with theoretical presumptions. The Joint Time Frequency Analysis applied on measurement data and its evaluation is described. It is well known that the Acoustic Emission Method is a very sensitive method to determine active cracks into structure. However, evaluation of acoustic emission signals is very difficult. A non-traditional method was used to signal analysis of burst acoustic emission signals recorded during three point bending test.

Abstract: . Polyurethane foam materials are widely used as cores in sandwich composites, for packing and cushioning. The main characteristics of foams are light weight, high porosity, high crushability and good energy absorption capacity. The paper presents the experimental results obtained for the mechanical properties of polyurethane foams in different loading conditions and the influence of impregnation on the mechanical properties. A 200 kg/m3 density polyurethane foam was investigated in the experimental program in three different Strength of Materials laboratories from Lublin, Bucharest and Timisoara. The paper assesses the possibility to describe the polyurethane foam behaviour trough compression tests, micromechanical models and Finite Element Analysis (FEA). The micromechanical models and Finite Element Analysis could be used successfully for representing the engineering stress – strain behaviour if the compression tests provide reliable material parameters.

Abstract: Polyurethane foam materials are widely used as cores in sandwich composites, for packing and cushioning. This paper presents the experimental results obtained for the mechanical properties of polyurethane foams in different loading conditions and the influence of impregnation on the mechanical properties. A 200 kg/m3 density polyurethane foam was tested in tension, compression and three point bending. The experimental results show that the impregnation layer has no effect on the strength of the foam, but has considerable influence on the tensile and flexure modulus.