Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 44 for “"Split-Hopkinson pressure bar"”.
-
Assessing the effect of friction on compression split Hopkinson pressure bar tests
… on accurate high strain rate material data. A Split Hopkinson Pressure Bar (SHPB) facility had previously been developed at the University of Cape Town to allow high strain rate testing of materials in compression. However, uncertainties regarding aspects of the test method that can affect the …
-
An Optical Method of Strain Measurement in the Split Hopkinson Pressure Bar
The split Hopkinson pressure bar (SHPB) continues to be one of the most common methods of testing materials at medium rates of strain. Elevated rates of strain, such as those found in impact and explosive applications, have been shown to induce phenomena such as strain hardening and phase …
-
High strain rate mechanical characterization of trabecular bone utilizing the split-Hopkinson pressure bar technique
The split-Hopkinson pressure bar (SHPB) technique has been in use in one form or another for more than fifty years and has recently gained a great deal of attention for its ability to characterize materials such as metals, plastics, and even stiff foams at strain rates of up to 105 sec-1. …
-
Development and proving of a split Hopkinson pressure bar used for high strain rate materials testing
… unusable. To overcome these limitations the split Hopkinson pressure bar (SHPB) was developed. A SHPB facility was developed at UCT to measure material properties at high strain rates. The development, discussed in this thesis, included the design and manufacturing of a SHPB, strain gauge …
-
High-Strain Rate Tensile Characterization Of Graphite Platelet Reinforced Vinyl Ester Based Nanocomposites Using Split-Hopkinson Pressure Bar
… tests are performed applying the reverse impact Split Hopkinson Pressure Bar (SHPB) technique. The specimen geometry for tensile test is parametrically optimized by Finite Element Analysis (FEA) using ANSYS Mechanical APDL®. Uniform stress distribution within the specimen gage length has been …
-
Low to high strain rate deformation of amorphous polymers : experiments and modeling
… (DMA), a servo-hydraulic testing machine and a split-Hopkinson pressure bar. Tension tests on the DMA were used to characterize the time-temperature dependence of the elastic storage moduli and the loss factors of the two polymers. The DMA data provided a quantification of the rate-dependent …
-
Development of a High Strain-Rate Constitutive Model for Sands and its Application in Finite Element Analysis of Tunnels Subjected to Blast
… rate-independent triaxial compression test and split Hopkinson pressure bar test. The model is implemented in the finite element software Abaqus through user defined material subroutines. Finite element simulations of the split Hopkinson pressure bar experiments on Ottawa and Fontainebleau sands …
-
Failure of Microelectromechanical Systems Under Dynamic Loading: An Experimental and Numerical Investigation
… Experiments were conducted using the modified split hopkinson pressure bar to investigate the effects of loading amplitude, duration, and profile on the failure of the cantilever beams. Finite element simulations of these beams were conducted to provide more detailed information regarding the …
-
Numerical investigation of dispersion in Hopkinson Pressure Bar
The Hopkinson Pressure Bar (HPB) is used as a load-time or displacement-time transducer in impact or blast experiments. The Split Hopkinson Pressure Bar (SHPB) is the accepted form of material testing for strain rates between 102 S-I and 104 S-I. Explicit Finite Element Analysis (FEA) codes are …
-
Implementation of viscoelastic Hopkinson bars
… soft or low impedance materials using metallic bars in a split Hopkinson pressure bar setup, poor signal to noise ratios and impedance mismatching occur. One solution is to use polymeric Hopkinson bars. In this dissertation, Polycarbonate, Polymethyl Methacrylate and Nylon are considered for use …
-
MODELLING AND SIMULATION MICROMACHINING OF THE ADDITIVELY MANUFACTURED METAL PARTS
… quasi-static compressive mechanical response and split-Hopkinson pressure bar tests of SLMed 316L to identify Johnson-Cook constitutive model constants; quasi-static tensile mechanical response and split-Hopkinson tensile bar tests to identify dynamic damage model constants for SLMed 316L …
-
Machining of additively manufactured titanium Ti-6Al-4V; cutting forces and chip morphology
… determined through time-consuming and costly split-Hopkinson pressure bar tests. The proposed model uses a combination of experimentally measured cutting forces and optimization methods including genetic algorithm and particle swarm optimization to find the suitable J-C parameters. Force …
-
Multiscale Experimental Study on the Effect of Texture and Anisotropy on the Thermomechanical Response of Zirconium
The adiabatic compression of metals in the split-Hopkinson pressure bar is associated with a rise in temperature due to the dissipation of work energy. High strain rate compression experiments on zirconium are carried out to investigate a possible dependence of dissipation on deformation mechanism. …
-
Finite strain behavior of polyurea for a wide range of strain rates
… (0.001/s to 10/s). Second, two distinct gas-gun split Hopkinson pressure bar [SHPB] systems are employed to cover high strain rates: a nylon bar system (700/s to 1200/s) and an aluminum bar system (2300/s to 3700/s). Lastly, the rate-sensitivity for intermediate strain rates (10/s to 1000/s) is …
-
Thermomechanical properties of polyhedral oligomeric silsequioxane- poly(methyl methacrylate) nanocomposites
… tension (strain rate = ... ) and high rate split-Hopkinson pressure bar tests (strain rate = ... ). In particular, the combined addition of two distinct POSS species - one miscible, one immiscible - led to the greatest enhancement in toughness and excellent reproducibility. A four-fold …
-
An investigation into the characterisation of the spalling behaviour of Polycrystalline Diamond Compact(PDC) cutters under impact loading conditions
… the degree of spalling was performed using the split-Hopkinson pressure bar (SHPB) apparatus. The PDC cutters were loaded under specific impact conditions and their reactions monitored and characterised. In order to isolate and identify the mechanism responsible for the spalling of the PDC …
-
Dynamic response of glass under low-velocity impact and high strain-rate compression loading
… drop weight impact test system, and a modified Split Hopkinson Pressure Bar (SHPB). In the low-velocity punch-shear experiment, similar trend has been observed for all glass types, and Starphire and Borosilicate demonstrated the highest total energy absorption. High strain-rate SHPB compression …
Page 1 of 3