Papers by Keyword: Tensile Test

Abstract: Blending polymers is an effective method to develop novel materials, tailoring the properties of the components. However, different morphology structures can be formed during the preparation, which could result in a wide diversity of mechanical and physical properties. The properties of polymer blends are most significantly influenced by the emerging range of phase inversion, which depends on the composition ratio and the viscosity ratio. In this paper various blends were prepared, utilizing polyethylene terephthalate (PET), polystyrene (PS) and two high density polyethylenes (HDPE), which differ in flowability. After preliminary homogenization by twin screw extruder, standard injection moulded specimen were prepared in order to present the effects of phase inversion on tensile properties, shrinkage and burning characteristics in binary polymer blends.

Abstract: The tensile test has been developed to assess scale adhesion of hot-rolled steel. The tensile testing machine was equipped with the CCD camera to follow the failure of scale during straining. The hot-rolled steel with different silicon content was used to investigate the scale adhesion behavior. The result is shown the mechanical adhesion energy of scale formed on the hot-rolled steel with higher Si contain was 115 J.m^-2, higher than the hot-rolled steel with lower Si contain which was 56 J.m^-2. This might be due to the presence of oxide containing Si at interface which promoted adhesion, implying that longer time for descaling would be required.

Abstract: In aluminum alloy sheet metal forming process, annealing treatment can improve the mechanical properties. The tensile test for different temperatures of 400°C, 450°C, 500°C, 550°C respectively have been carried out from 1h to 12h.The result revealed that the ductility increased with the increase of annealing temperature. It is found that the annealing treatment at 500°C for 6 h can get a good property. Furthermore, the result of tensile test showed that the yield strength increased from 130MPa before cold rolling to 190MPa after annealed, and the elongation of the sheet increased to 28.6%. The result of stamping test verified that the limiting draw ratio (LDR) increased after annealing treatment from 1.15 to 1.56. The value of blank holder force for the cylindrical cup is becoming smaller after the annealing treatment. The microstructure investigations on experimental aluminum alloys after long-time annealing and cold rolling conditions were presented. The changes of the main structural contituents have been obviously observed, which improved the formability of the alloys.

Abstract: This paper deals with a testings of the Selective Laser Melting (SLM) process parameters on mechanical properties, material behavior, surface quality and on machinability of austenitic steel 316L. The SLM process conditions were changed to assess their effect on mechanical properties of the sintered material measured in tensile testing. The laser power, the scanning velocity of laser beam, the layer thickness and the laser focus plane were set to find the most appropriate set of process parameters to obtain the mechanical properties of parts.

Abstract: Dynamic recrystallization in Ti-1100 was investigated. Ti-1100 is one of near α titanium alloys and contains Si for improving high temperature mechanical properties. Ti-1100 exhibits martensitic transformation by quenching into iced brine after solid solution treatment. Hereafter specimens subjected to quenching into iced brine and to cooling in air after solid solution treatment are called IBQ specimen and AC specimen, respectively. After tensile test at high temperature, IBQ specimen exhibits morphological change from lath structure to equiaxed structure, but AC specimen does not. It is indicated that dynamic recrystallization occurs during the tensile test of IBQ specimen. Effect of silicide on the dynamic recrystallization was investigated using two specimens: one included more silicide precipitates and the other less. The former specimen shows smaller recrystallized grains than the latter. It is indicated that the specimen including more silicides exhibits smaller recrystallized grains.

Abstract: A micro-scale interface strength evaluation technique is essential for evaluating cold-sprayed materials. A focused ion beam (FIB) micro strength test enables the micro-scale evaluation of the interface mechanical properties. However, this technique cannot be used to measure the strain in a specimen. This work discusses the possibility of strain measurement by combining this technique with image analysis in a newly designed test setup. Moreover, the micro stress-strain curve for cold-sprayed copper was obtained. This improved method enables us to measure stress with a precision of 5 MPa and strain with a precision of 0.015. It was determined that some local regions can deform plastically, which could not be determined with conventional micro-and macro-scale evaluation methods. These results proved that the coating is non-uniform, while also revealing various microstructure and mechanical properties.

Abstract: Structural adhesives methods for joining multi material sheets have been focus of studies and researches for the last years. The most common and widely known type of test is the tensile test of single lap joints (SLJ). However, there are opportunities for analyzing the mechanical performance of such method in SLJ with materials of different properties, such as ductile structural aluminum alloys and high strength steels. It’s also known that the stress state of SLJ, when stressed longitudinally, generates secondary forces. One of them is known as cleavage force which initially leads to the failure of bonded joints. The aim of this work is to analyze the stress state of similar and dissimilar materials SLJ submitted to tensile stresses and also the influence of some variables, such as overlap length, adhesive film thickness and adherend yield limit, over the stress strength of the samples. As adherend materials it was selected the structural aluminum alloy AA 5083 H111 and the high strength steel DP600. At the end of this work it is expected to understand the proper stress state of the SLJ when using similar and dissimilar materials, identifying stress concentrators that bring the structure to fail, using the Digital Image Correlation (DIC) method. It was discovered that the yield strength associated with the overlap length highly influences the SLJ strength, by leading it to a close to pure adhesive shear stress state.

Abstract: The preservation of brick masonry buildings and historically significant buildings is a very hot topic today. A problem that often occurs during reconstruction and modernization is an optimal solution between price and efficiency. First of all, it is necessary to view the object as a complex system, when it is necessary to ensure its spatial rigidity. Planning and progress of reconstruction is then derived from the correct assessment of the building. The spatial rigidity of buildings in the past was also ensured by means of reinforcing elements. For masonry buildings, wall and beamed ties have been used for this purpose until the end of the 19th century. Since these wrought ties are made of a completely different material so-called wrought iron, its properties are different from the currently used materials. They differ in both tensile strength and other properties just because of other processing technology and manufacturing. At the time of the construction of the buildings it was not possible to provide a variety of length of the ties, so that ties have been joined by forged connections or adjustable wedge relations. The article deals with determining the tensile strength of wrought ties obtained by destructive methods. The results of the experiment may serve to predict the behaviour of ties from a similar period.

Abstract: Bioplastics have attracted attention over the years from a perspective of environmental protection. Recently, attention is focused on bioplastics derived from inedible objects. Polyhydroxyalkanoates (PHAs) are known as a microbial origin plastic and expected to deal effectively with the food security issue. In this study, in order to use PHA for industrial and machinery parts and products, polycaprolactone (PCL) was blended with a PHA-based pellet to improve ductility and tensile strength. The effects of additives on tensile strength and elongation at break, dynamic tensile tests of the polymer blends were examined using split Hopkinson bar (SHPB) method at high strain rates.

Abstract: This paper studies the mechanical properties of the aramid fiber reinforced epoxy resin composite by varying the percentage composition. Three different compositions of aramid fiber are 30 %, 35 % and 45 % by weight. The aramid epoxy composite was manufactured by the vacuum suction method. The manufactured composites are then cured by the hot air oven for 180 minutes. The prepared composites undergo through various tests such as the tensile test, hardness test and impact test. The results of the tests on the three compositions analyzed and variation in its mechanical properties is noted.