Papers by Keyword: Tensile Experiment

Abstract: The process of destruction of cylindrical samples under uniaxial tension is described taking into account changes in the geometry of the sample. An approach is formulated to determine the failure constants in the form of invariant characteristics based on standard mechanical tests under conditions of axisymmetric deformation.

Abstract: Conducting tensile experiment with high pressure gas cylinder materials to analyze its acoustic emission (AE) signals, can realize the stretch features and AE signals regularity, which is very important to distinguish high pressure gas cylinder detection. The AE signals are divided into four different stages through the tensile experiment, which show that AE signals and theory analysis are fitted well and thus be used to distinguish materials defects.

Abstract: The elastic-plasticity of the titanium alloy material has certain effect on the stability of the milling system. When the material is incompressible, the curve and the simple tensile curve are the same, and the material’s curve and the one-way shear’s curve are also the same. This may be called single curve theory. This paper is, under simple loading conditions, gets the data in the titanium alloy’s tensile experiment and torsion experiment. It studies the constitutive relation in the state of the multidimensional stress and the strain, by the material data obtained in the simple tensile experiment and torsion experiment according to the single curve theory. In the simple loading condition, it obtains the data of the titanium alloy’s tensile experiment and torsion experiment, and then gets the titanium alloy’s incremental constitutive relation, and by integration, it gets the constitutive relation of the titanium alloy’s total strain theory.

Abstract: The design and process of diaphragms for a welded bellow was studied in this paper, which is a flexible component in a piping system or vacuum equipment. Due to a lot of interactive effects on each procedure in the manufacturing for a welded bellow, furthermore the commercial FEM software ANSYS was used to construct a 3-dimension model for the displacement and modal analysis of bellows in which extensions and natural frequencies as well as mode shapes could be observed. The mechanical feature should be considered at the practical applications, i.e., to avoid the occurrence of resonant phenomena corresponding to pump operations and fluid delivery in a piping system. For the purpose of modeling validation, the axial tensile testing machine implemented the extension experiment for welded bellows. According to the results of simulation and experiment, the difference among them could be easily detected for the feature investigation for a design-oriented systemic analysis on the development of welded bellows.

Abstract: Polypropylene specimens were made by the injection molding experiments under different processing conditions. The crystallinity of each polypropylene specimen was obtained using the X-ray diffraction method. The effects of the injection molding processes on the crystallinity of polypropylene were revealed: (1) the crystallinity decreases as the melt temperature increases, and the higher the melt temperature, the slower the crystallinity decreases, (2) the crystallinity decreases as the mould temperature increases, and the higher the mould temperature, the faster the crystallinity decreases, (3) the crystallinity increases as the injection speed increases, and the larger the injection speed, the faster the crystallinity increases. By the tensile experiments of the injection molded specimens, it is also found that the crystallinity has a major impact on the mechanical properties of polypropylene. The yield strength and tensile strength of polypropylene specimens increase as the crystallinity increases.

Abstract: By the macroscopic tensile tests of the 3D four-directional braided composites, the failure pattern and fracture morphology of specimens with different geometric sizes have been observed. It is obtained that the different failure mechanisms and the material properties are relevant to the geometric sizes of samples under tensile states. The elastic properties of the braided composites are obtained by volume average method. The variation of shear modulus and Poisson ratio is obtained as well. It is shown that the elastic modulus increases with the increase of number of interior cells. The predicted results are in agreement with the experimental results. The results may provide experimental basis for further study on strength prediction and the establishment of strength criterion for 3D four-directional braided composites.

Abstract: Understanding the dynamic behavior of concrete in rapid loading is an issue of great importance in civil engineering. In this study, an experimental program was performed to investigate the dynamic behavior of concrete subjected to different strain-rate loadings. From the test results the rate-dependent effect on the ultimate strength of concrete was confirmed, i.e., the strength increases with the increasing strain rate. The dynamic failure process of concrete in tension and physical mechanism were discussed based on the experimental observations.