Three-Dimensional Effects Near a Crack Tip in a Ductile Three-Point Bend Specimen: Part II—An Experimental Investigation Using Interferometry and Caustics

1990 ◽  
Vol 57 (3) ◽  
pp. 618-626 ◽  
Author(s):  
Alan T. Zehnder ◽  
Ares J. Rosakis
Keyword(s):  
Experimental Investigation ◽  
Large Scale ◽  
Three Dimensional ◽  
Time History ◽  
Fracture Initiation ◽  
Optical Methods ◽  
J Integral ◽  
Bend Specimen ◽  
Dimensional Effects ◽  
Point Bend

An experimental investigation is undertaken to assess three-dimensional effects near a crack front in a ductile three-point bend specimen. The possibility of using the optical method of caustics for the measurement of the J-integral in the presence of large-scale yielding and three-dimensional fields is also investigated. Experiments using the optical methods of caustics by reflection and Twyman-Green interferometry are performed simultaneously on either side of the test specimen. The load and load-point displacement are also measured. The experimental results are compared with very good agreement to the results of a finite element simulation of the experiment. The caustics experiments are used to obtain a calibration relation between the value of the J-integral and the caustic diameter for load levels up to fracture initiation. It is proposed that such a calibration be used in dynamic fracture initiation experiments for the measurement of the time history of the dynamic J-integral.

Three-Dimensional Effects Near a Crack Tip in a Ductile Three-Point Bend Specimen: Part I—A Numerical Investigation

1990 ◽  
Vol 57 (3) ◽  
pp. 607-617 ◽  
Author(s):  
R. Narasimhan ◽  
A. J. Rosakis
Keyword(s):  
Plane Strain ◽  
Plane Stress ◽  
Crack Front ◽  
Three Dimensional ◽  
Crack Tip ◽  
Upper And Lower Bounds ◽  
Thickness Variation ◽  
Bend Specimen ◽  
Dimensional Effects ◽  
Point Bend

A simultaneous numerical and experimental investigation is undertaken to assess three-dimensional effects and HRR dominance near a crack front in a ductile 3-point bend specimen. In parallel to the three-dimensional calculations, a plane-strain and a plane-stress analysis of the same in-plane specimen geometry is performed to obtain upper and lower bounds for the three-dimensional calculation. The radial, angular, and thickness variation of the stresses and displacements are studied in great detail from contained yielding to fully plastic conditions. The results indicate that the plane-strain HRR field prevails in the interior of the specimen very near the crack front even for moderate extents of yielding. On the other hand, for distances from the crack tip exceeding about half a specimen thickness, plane-stress conditions are approached. The calculations presented here model a series of laboratory experiments involving three independent experimental techniques. Details regarding the experiments and comparisons of the experimental measurements with numerical calculations and theory are emphasized in Part II of this work.

scholarly journals Study on Fluorine Pollution in a Slag Yard

2019 ◽  
Vol 9 (5) ◽  
pp. 847
Author(s):  
Lide Wei ◽  
Changfu Wei ◽  
Sugang Sui
Keyword(s):  
Numerical Simulation ◽  
Experimental Investigation ◽  
Numerical Simulations ◽  
Solute Transport ◽  
Large Scale ◽  
Three Dimensional ◽  
Simulation Method ◽  
Laboratory Studies ◽  
Survey Results ◽  
Simulation Results

This paper suggests a large-scale three-dimensional numerical simulation method to investigate the fluorine pollution near a slag yard. The large-scale three-dimensional numerical simulation method included an experimental investigation, laboratory studies of solute transport during absorption of water by soil, and large-scale three-dimensional numerical simulations of solute transport. The experimental results showed that the concentrations of fluorine from smelting slag and construction waste soil were well over the discharge limit of 0.1 kg/m3 recommended by Chinese guidelines. The key parameters of the materials used for large-scale three-dimensional numerical simulations were determined based on an experimental investigation, laboratory studies, and soil saturation of survey results and back analyses. A large-scale three-dimensional numerical simulation of solute transport was performed, and its results were compared to the experiment results. The simulation results showed that the clay near the slag had a high saturation of approximately 0.9, consistent with the survey results. Comparison of the results showed that the results of the numerical simulation of solute transport and the test results were nearly identical, and that the numerical simulation results could be used as the basis for groundwater environmental evaluation.

An Experimental Investigation of the Three-Dimensional Flow Within Large Scale Turbine Cascades

1986 ◽  
Author(s):  
Jaromír Jílek
Keyword(s):  
Experimental Investigation ◽  
Large Scale ◽  
Three Dimensional ◽  
Side Wall ◽  
Aerodynamic Characteristics ◽  
Flow Measurements ◽  
Wall Boundary Layer ◽  
Flow Parameters ◽  
Side Walls ◽  
Turbine Cascades

A detailed experimental investigation of the three-dimensional subsonic flow was carried out in a typical nozzle and impulse configuration of plane turbine cascades with a chord length 0.5 m. Flow parameters were measured within the passage and behind the cascade using a five-hole probe. Pressure distribution measurements and flow visualization were made on blade surfaces and side walls. Flow measurements were taken in endwall and airfoil boundary layers for both types of cascades. The influence of the aspect ratio, the inlet side wall boundary layer and the position of traversing planes on aerodynamic characteristics and losses is discussed.

scholarly journals A simple method for evaluating the J-integral of an impacted three-point bend specimen.

1987 ◽  
Vol 53 (489) ◽  
pp. 899-904 ◽  
Author(s):  
Kikuo KISHIMOTO ◽  
Arata SUZUKI ◽  
Shigeru AOKI ◽  
Masaru SAKATA
Keyword(s):  
J Integral ◽  
Bend Specimen ◽  
Simple Method ◽  
Point Bend

Development Of Large-Scale Three-Dimensional Seismic Ground Strain Response Analysis Method and Its Application to Tokyo using Full K Computer

2016 ◽  
Vol 10 (05) ◽  
pp. 1640017 ◽  
Author(s):  
Kohei Fujita ◽  
Tsuyoshi Ichimura
Keyword(s):  
Degrees Of Freedom ◽  
Large Scale ◽  
Three Dimensional ◽  
Time History ◽  
Response Analysis ◽  
Target Area ◽  
Strain Response ◽  
Analysis Method ◽  
Ground Structure ◽  
Modeling And Analysis

We developed a large-scale three-dimensional ground analysis method aimed at improving the estimation of dynamic ground strain during earthquakes. Using the developed ground modeling and analysis method, a 40 billion degrees-of-freedom unstructured finite element ground model of a 3.25[Formula: see text]km × 3.25[Formula: see text]km area of Tokyo was generated with 0.66[Formula: see text]m sized elements, and its strain time history for ground motion of the 1995 Kobe wave was computed using the full K computer system with 82,944 compute nodes. The obtained strain response showed a complex distribution reflecting the input wave characteristics, surface topography, and underlying ground structure. We also showed the seismic response of 41,675 buildings in the target area computed using the wave at surface as an input. Such a method is expected to be useful for the improvement of seismic design and mitigation of pipelines against anticipated earthquakes.

Sign in / Sign up

Export Citation Format

Share Document