Dynamic Fracture of 6061-T6 Aluminum Cylinders

1977 ◽  
Vol 44 (4) ◽  
pp. 643-646 ◽  
Author(s):  
D. L. Wesenberg ◽  
M. J. Sagartz
Keyword(s):  
Wave Propagation ◽  
Dynamic Fracture ◽  
Capacitor Bank ◽  
Magnetic Pressure ◽  
Strain Rates ◽  
Radial Expansion ◽  
Material Parameters ◽  
Subsequent Fracture ◽  
Thin Walled ◽  
Good Agreement

Radial expansion and subsequent fracture into segments of thin-walled cylindrical shells at large initial strain rates are studied analytically and experimentally. The theory of probability along with a description of relief wave propagation away from each fracture is used to formulate a theory which predicts the number of fractures and the distribution of fragment lengths. Eleven 6061-T6 Aluminum cylinders were expanded at strain rates of ∼104 s−1 by magnetic pressure pulses from a capacitor bank discharge, and these results are compared with predictions. Good agreement is shown between experimental results and predictions. In addition, the physical and material parameters to which the problem is sensitive are discussed.

The Plastic Buckling of Thin-Walled Tubes Subject to Magnetomotive Forces

1974 ◽  
Vol 16 (2) ◽  
pp. 59-70 ◽  
Author(s):  
S. T. S. Al-Hassani
Keyword(s):  
Aluminium Alloy ◽  
Radial Displacement ◽  
Capacitor Bank ◽  
Magnetic Pressure ◽  
Experimental Results ◽  
Tube Length ◽  
Current Waveform ◽  
Hoop Strain ◽  
Plastic Buckling ◽  
Thin Walled

Aluminium alloy tubes and rings can be reduced in diameter by means of external coils through which a large capacitor bank is discharged, due to the high radial transient magnetic pressure. Both the radial and perturbed motions are investigated theoretically and experimentally. Predictions of the current waveform, radial displacement and the number of wrinkles on the tube agree well with the experimental results. The number of wrinkles increases with tube length and diameter. However, geometrically similar tubes, when reduced to the same final hoop strain, have similar buckled shapes with the same number of wrinkles.

Calibrating material parameters to model the thin-walled components made of die cast AM60B magnesium alloy

2012 ◽  
Vol 17 (5) ◽  
pp. 540-552 ◽  
Author(s):  
Feng Zhu ◽  
Clifford C. Chou ◽  
King H. Yang ◽  
Xiaoming Chen ◽  
David Wagner ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Material Parameters ◽  
Die Cast ◽  
Thin Walled

scholarly journals Measurement of fracture energy of concrete at high strain rates

2018 ◽  
Vol 183 ◽  
pp. 02065
Author(s):  
V. Rey-de-Pedraza ◽  
F. Gálvez ◽  
D. Cendón Franco
Keyword(s):  
Tensile Strength ◽  
Fracture Energy ◽  
Dynamic Fracture ◽  
Dynamic Properties ◽  
Hopkinson Bar ◽  
Experimental Information ◽  
Tensile Fracture ◽  
Strain Rates ◽  
Dynamic Tensile Strength ◽  
Conventional Concrete

The Hopkinson Bar has been widely used by many researchers for the analysis of dynamic properties of different brittle materials and, due to its great interest, for the study of concrete. In concrete structures subjected to high velocity impacts, initial compression pulses travel through the material leading to tensile stresses when they reach a free surface. These tensile efforts are the main cause of concrete fracture due to its low tensile strength compared to the compressive one. This is the reason why dynamic tests in concrete are becoming of great interest and are mostly focused in obtaining tensile fracture properties. Apart form the dynamic tensile strength, which has been widely studied by many authors in the last decades, the dynamic fracture energy presents an increased difficulty and so not too much experimental information can be found in literature. Moreover, up to date there is not a clear methodology proposed in order to obtain this parameter in an accurate way. In this work a new methodology for measuring the dynamic fracture energy is proposed by using the Hopkinson Bar technique. Initial tests for a conventional concrete have been carried out and the results for the dynamic fracture energy of concrete at different strain rates are presented.

Torsional Stiffness of a Thin-Walled Beam Braced by Pinned or Rigidly Fixed Transverse Diaphragms

1973 ◽  
Vol 15 (5) ◽  
pp. 351-356
Author(s):  
T. Harrison ◽  
J. M. Siddall
Keyword(s):  
Experimental Evidence ◽  
Theoretical Work ◽  
Torsional Stiffness ◽  
Cross Sectional ◽  
Cross Sectional Profile ◽  
Thin Walled ◽  
Sectional Profile ◽  
Good Agreement

The torsional stiffness of a thin-walled beam of open cross-sectional profile braced by evenly spaced transverse diaphragms is studied. Diaphragms rigidly fixed or attached by frictionless pins are treated and it is seen that, in either case, the only effect is to modify the St Venant torsional constant for the thin-walled beam. The theoretical work is supported by experimental evidence from two braced perspex channels which simulate the two assumed methods of attaching the diaphragms. Good agreement is demonstrated.

scholarly journals Design analysis of four-wave-mixing in SiN nanowires integrated with graphene oxide films

2020 ◽  
Author(s):  
David Moss
Keyword(s):  
Graphene Oxide ◽  
Kerr Nonlinearity ◽  
Four Wave Mixing ◽  
Wave Mixing ◽  
Trade Off ◽  
Material Parameters ◽  
Highly Nonlinear ◽  
Thermal Changes ◽  
Strong Mode ◽  
Good Agreement

<p>We theoretically investigate and optimize four-wave mixing (FWM) in silicon nitride (SiN) waveguides integrated with two-dimensional (2D) layered graphene oxide (GO) films. Based on extensive previous measurements of the material parameters of the GO films, we perform detailed analysis for the influence of device parameters including waveguide geometry, GO film thickness, length, and coating position on the FWM conversion efficiency (CE) and conversion bandwidth (CB). The influence of dispersion and photo-thermal changes in the GO films is also discussed. Owing to the strong mode overlap between the SiN waveguides and the highly nonlinear GO films, FWM in the hybrid waveguides can be significantly enhanced. We obtain good agreement with previous experimental results and show that by optimizing the device parameters to balance the trade-off between Kerr nonlinearity and loss, the FWM CE can be improved by as much as ~20.7 dB and the FWM CB can be increased by ~4.4 folds, relative to the uncoated waveguides. These results highlight the significantly enhanced FWM performance that can be achieved in SiN waveguides by integrating 2D layered GO films.<i></i></p>

Dynamic Analysis of Fracture in Thin-Walled Pipes

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
C. Gato ◽  
Y. Shie
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Fracture ◽  
Meshfree Method ◽  
Meshfree Methods ◽  
Shape Functions ◽  
Order Continuity ◽  
Cylindrical Structures ◽  
Thin Walled Structures ◽  
Ill Conditioning ◽  
Thin Walled

Dynamic fracture of thin-walled cylindrical structures is studied with a large deformation meshfree method. Due to the higher order continuity and smoothness of the shape functions, meshfree methods are well suited to simulate dynamic fracture of thin-walled structures since they avoid ill-conditioning as well as stiffening in numerical computations. Simulations of detonation driven fracture in thin pipes demonstrate the efficiency of the method.

Meshless Simulation of Fracture in Thin-Walled Pipe Structures

2009 ◽  
Author(s):  
S. J. Liu
Keyword(s):  
Dynamic Fracture ◽  
Fracture Criterion ◽  
Sph Method ◽  
Shell Analysis ◽  
Stress Point ◽  
Particle Hydrodynamics ◽  
Thin Walled Pipe ◽  
Smoothed Particle ◽  
Point Integration ◽  
Thin Walled

A meshless shell method for dynamic fracture problems based on normalized Smoothed Particle Hydrodynamics (SPH) is presented. The SPH method is corrected by a normalization in order to fulfill completeness requirement. Instability are controlled by stress-point integration. The method is modified for Mindlin-Reissner shell analysis. Stress based fracture criterion is incorporated based on the visibility method. The method is applied to two dynamic fracture problems in thin-walled pipes including fluid-structure interaction. The results are compared to experimental data and they are very promising.

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