Papers by Keyword: Simple Shear Test

Abstract: A noval concrete structure strengthening technique which employs aluminum alloy plate of stiffened sections was presented. Aluminum plate width, stiffener number and height were considered for bond performance investigations. Based on the simlple shear test, three types of failure mode were observed in this study. Test results indicates that the couple effect of aluminum width and stiffener number is more remarkable than stiffener height for strengthening behaviour. A set of comparison over the behaviour of aluminum laminate were carried out among EBR, NSM and stiffened plates. It shows that the siffened plates can be used sucessfully in concrete strengthening.

Abstract: This paper presents an experimental study on the bond performance of aluminum alloy plate-to-concrete interface via a series of simple shear test. The parameters examined include the bond length and width of the aluminum alloy plates. Two types of failure modes were observed through the experimental program. The test results demonstrate the bond strength of the aluminum plate-to-concrete interface depends strongly on the coupling effect of bond length and width. The variation of the aluminum strain distribution along the bond length against the applied load clearly illustrates the existence of an effective bond length. The load-slip curves show that the bond width has more sensitive effect to the bond strength.

Abstract: A series of soil-structure shear tests was taken by self-made large single shear apparatus and the main factors affecting behavior of the interface are studied. It was shown that the deformation and mechanical properties are determined by the roughness of structural surface, particle size distribution and normal stress. The interface deformation includes the shear deformation of the soil near the structure due to the constraint of structural surface and the slipping deformation of soil-structure interface, they happen at the same time and interact each other . The thickness of the interface element is 4 to 5 times of the average particle diameter away from the structure surface.

Abstract: Complex material models used for the numerical representation of forming processes need in addition to tension and compression tests also shear tests to completely analyse the behaviour of the material under different loading conditions. There are two concepts of shear test one uses symmetrical specimens with two shear zones (according to Miyauchi) the other one specimens with a single shear zone. In both cases, a homogeneous distribution of the strain in the shear zone is essential for the validity of the shear test. Therefore, the length and width of the shear zone in a single shear specimen made from high strength steel according to the ASTM standard geometry were varied. Analysing the resulting strain distribution numerically an optimised sample geometry with a more uniform strain distribution than the ASTM standard was achieved. The numerical results were also validated with experimental shear tests.

Abstract: The application of modern materials plays an important role directly under the aspect of lightweight potential. To exploit these options effectively a numerical accurate reproduction of the material behavior is indispensable. Especially in the case of large deformations a directional and strain rate dependent hardening behavior can be observed. By disregarding this effect significant failure in the computed stress state can arise, which can conduct to a corruption of the spring-back forecast. Within this contribution a new test method for analyzing the evolution of subsequent yield loci under strain path changes for the aluminum alloy AA6016 and the deep drawing steel DC06 is presented. In the first stage of the experimental investigations, yield loci with linear strain paths were considered to characterize the material behavior for the initial condition. On further experiments with several stress states the strain path dependent hardening behavior of the material is determined. The non-linear strain paths are realized through uniaxial prestrained primary specimens with following extraction of secondary samples for following stress states, e.g. a modified ASTM simple shear test specimen. Subsequent yield loci are investigated and compared to the yield surfaces Hill48 and Barlat 2000 (Yld2000-2d) with an isotropic hardening behavior. With this study the evolution of the yield locus for prestrained specimens is evaluated. The research of the subsequent yield loci for strain path changes serves as basis for further scientific investigations with a view to assess different approaches of isotropic-kinematic hardening models in consideration of the analyzed steel and aluminum sheet metals.

Abstract: Soil saturation degree plays an important role in mechanic behavior of soil-concrete interface. Laboratory experiments are conducted on soil-concrete interfaces by using improved simple shear apparatus, where three soil saturation degrees and five normal stresses are taken into accounted, respectively. The experiment data show that failure of the interface still satisfies the Mohr-Coulomb criterion under fixed soil saturation degree. With higher soil saturation degree, both shear strength and friction angle of the interface decrease monotonously, but cohesion force of the interface first increases and then decreases after reaching a peak value. When soil saturation degree increases, failure position of the interface moves from concrete surface to soil inner part.

Abstract: Some of new severe plastic deformation processes as equal channel angular extrusion, and strip shearing are presented as very efficient techniques for grain refinement. Channel geometry, contact friction, strain rate and multi-pass processing versus microstructure and mechanical properties are shown.

Abstract: Although the Taylor-type models gives reasonable texture prediction of the monotonic cold deformation of annealed aluminum alloys both qualitatively and quantitatively, results are less satisfactory for the simple shear test when the alloy is heavily pre-deformed by cold rolling. The reason for this less good prediction originates from strain localization. A virtual stress-strain curve is proposed in which the texture aspects are dealt with by the FC Taylor simulation and the microstructure aspects by a model for the development of intragrain dislocations structure. This virtual yield law is used in a finite element simulation. A strain localization behavior is observed during the finite element simulation similar to that observed during experimental simple shear test. The strain profile of a specific global strain is discretized into a series of strain and the volume fractions of the regions deformed to these strain levels, using the statistical method of histogram. A secondary FC-Taylor simulation is performed, in order to generate the deformation textures, corresponding to this series of deformation strains. The global texture is generated by merging these textures with consideration of these volume fractions. Using this procedure of multi-level modeling, quite satisfactory texture prediction is observed, compared with the measured texture at this strain.