Download or read book Determination of Dynamic Fracture Behavior in 4340 Steel Compact Crack Arrest Specimens Using Birefringent Coatings and Finite Element Analysis written by DB. Barker and published by . This book was released on 1988 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: A split-birefringent coating technique, coupled with high-speed photography, was used to record the dynamic isochromatic fringe pattern associated with crack propagation and arrest in 4340 steel compact crack arrest fracture specimens. From the data contained in the isochromatic fringe patterns, the associated dynamic stress-intensity factor was calculated in two different ways. First, the dynamic stress-intensity factor was calculated from the isochromatic fringe information directly. Next, the isochromatic fringe patterns were used to obtain a crack position history which was used for input to a two-dimensional dynamic finite-element code used in the "generation mode." These two dynamic stress-intensity factors were compared with each other and with the crack arrest toughness as calculated by the proposed ASTM method for estimating crack arrest toughness.
Download or read book Fracture Mechanics Nineteenth Symposium written by Thomas A. Cruse and published by ASTM International. This book was released on 1988 with total page 936 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fracture Mechanics written by and published by . This book was released on 1988 with total page 960 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photoelastic Studies of Crack Propagation and Crack Arrest in Polymers and 4340 Steel written by George Rankin Irwin and published by . This book was released on 1978 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Some Aspects of Performing Dynamic Measurements and Analyses on the Compact Crack Arrest Specimen for A533 B Steel written by B. Brickstad and published by . This book was released on 1988 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: The four countries of Sweden, Norway, Finland, and Denmark are participating in a joint project which includes performing instrumented crack arrest experiments on A533-B steel. The primary aim of this study is to determine the dynamic fracture properties during propagation and arrest. Dynamic finite-element methods calculations were used to analyze earlier reported experiments on the transverse wedge-loaded compact crack arrest (CCA) specimen, in order to obtain guidance for future experiments regarding measuring technique, material characterization, and the crack-tip model. The computations indicate that the dynamic effects on the stress-intensity factor are small for the CCA specimen. It is also shown that proper determination of the displacement controlled boundary conditions can be made by measuring displacements at the load line. Computations were also made with the material treated as elastic-viscoplastic. It was found that nonlinear material behavior is likely to be important for A533-B steel at least at room temperature and higher temperatures.
Download or read book Metals Abstracts written by and published by . This book was released on 1988 with total page 812 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Crack Arrest Methodology and Applications written by and published by ASTM International. This book was released on 1978 with total page 445 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dynamic Photoelastic Determination of the a K Relation for 4340 Alloy Steel written by JW. Dally and published by . This book was released on 1980 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: A method of direct determination of the instantaneous stress-intensity factor associated with running and arrested cracks in steels has been developed at the University of Maryland. Birefringent coatings have been applied to the proposed ASTM standard crack arrest compact specimens of oil-quenched and tempered 4340 steel. Isochromatic fringe patterns during crack propagation and crack arrest have been photographed successfully with an ultrahigh-speed Cordin camera and specially designed high-intensity and short-duration Xenon lamp system.
Download or read book Fast Fracture and Crack Arrest written by George T. Hahn and published by ASTM International. This book was released on 1977 with total page 423 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Using Small Specimens to Measure Dynamic Fracture Properties of High Toughness Steels written by H. Conque and published by . This book was released on 1992 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of coupled pressure bars (CPB) to induce dynamic fracture in tough materials using small specimens is investigated. CPB experiments were performed with a nuclear pressure vessel steel, A533 Grade B Class 1, over the temperature range 37 to 100°C. The dynamic fracture initiation toughness at a stress intensity loading rate, KI, of 2 x 106 MPa•m1⁄2 s-1 was deduced from the simulation of the fracture experiment with a dynamic viscoplastic finite-element fracture code. At 100°C, no cleavage fracture was observed for either dynamic crack initiation or subsequent propagation and arrest. A procedure to measure initiation, propagation, and arrest toughnesses of nuclear pressure vessel steels up to service temperature with CPB specimens is introduced.
Download or read book Dynamic Fracture Toughness written by A. S. Kobayashi and published by . This book was released on 1985 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dynamic fracture toughness versus crack velocity relations of Homalite-100, polycarbonate, hardened 4340 steel and reaction bonded silicon nitride are reviewed and discrepancies with published data and their probable causes are discussed. Data scatter in published data are attributed in part to the observed fluctuations in crack velocities. The results reaffirmed our previous conclusion that the dynamic fracture toughness versus crack velocity relation is specimen dependent and that the dynamic arrest stress intensity factor is not a unique material property. Originator supplied keywords: Dynamic photoelasticity; Dynamic caustics; Dynamic crack arrest stress intensity factor.
Download or read book Dynamic Fracture Initiation and Propagation in 4340 Steel Under Impact Loading written by Alan T. Zehnder and published by . This book was released on 1986 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dynamic fracture initiation and propagation in 4340 steel was investigated experimentally using the optical method of reflected caustics combined with high speed photography. A new crack propagation testing configuration consisting of a three point bend specimen loaded in a drop weight tower was used. It was found that prior to crack initiation the stress intensity factor time record calculated using the dynamic tip load and a static formula disagrees with the actual stress intensity factor measured by caustics. During crack propagation, the crack tip velocity and stress intensity factor time records varied smoothly and repeatably allowing for a straightforward interpretation of the data. The experiments show that for the particular heat treatment of 4340 steel used, the dynamic fracture propagation toughness depends on crack tip velocity through a relation that is a material property. Keywords: Dynamic fracture initiation, Dynamic crack propagation, Caustics, 4340 steel, High-speed camera, Stress-intensity factor, and Three point bend specimen.
Download or read book Dynamic Fracture Behavior of Structural Materials written by J. H. Giovanola and published by . This book was released on 1986 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents results of a program to improve understanding of dynamic fracture behavior by investigating both crack tip loading conditions and material properties for fracture at high loading rates. A new test procedure, the one-point-bend test was analyzed and further developed the test a wide range of materials at impact loading rates. The test uses inertial loading to load the crack tip and affords an unambiguous measurement of the dynamic initiation toughness. The test's usefulness in producing small controlled increments of crack extension and in crack propagation studies was also demonstrated. Moreover, the concept of inertial loading was extended to study dynamic mixed- mode crack initiation under controlled mixed mode I and II conditions. These new test techniques were used to establish the dynamic fracture behavior of 4340 steel (HRC 50). It was shown that, for loading times to fracture as short as 20 microsecs, no time-modified criterion is necessary to predict crack initiation. The classical fracture criterion equating the applied stress intensity to the dynamic fracture toughness is adequate, provided the dynamically applied stress intensity is correctly evaluated. Under mixed mode I and II loading with (k sub II)/(k sub I) values between 0 and 0.5, it was demonstrated that dynamic crack initiation is essentially controlled by the mode I stress intensity and by the mode I dynamic fracture toughness.
Download or read book An Analysis Of and Some Observations On Dynamic Fracture in an Impact Test Specimen written by T. Nishioka and published by . This book was released on 1981 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerical simulations of crack-propagation histories in four cases of dynamic tear test experiments on 4340 steel are performed. The influence of the loss of contact of the specimen at various times with either the supports or the tup or both is critically examined. In each case, the variation of the dynamic K-factor, for the simulated crack-propagation history, is directly computed. The results are discussed in the light of current controversies surrounding the dynamic fracture toughness properties governing crack-propagation under impact loading. It is concluded that these controversies may not be fully warranted. (Author).
Download or read book Ceremonie reglement gegen fremde gesandten berathen unter den drey vororten und nach erfolgter zustimmung Z rich s und Luzern s in das eidgenossische protocoll unter dem 24ten dezember 1818 eingetragen written by and published by . This book was released on with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 1460 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Dynamic Fracture Mechanics The Albert S Kobayashi Anniversary Volume written by M. F. Kanninen and published by . This book was released on 1986 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Partial Contents: Fundamental considerations in dynamic fracture; The behaviour of cracks under thermal transient loading; Dynamic analysis of crack growth and arrest in a pressure vessel subjected to thermal and pressure loading; The role of crack arrest in the evaluation PWR pressure vessel integrity during PTS transients; A dynamic analysis of crack propagation and arrest in pressurized thermal shock (PTS) experiments; A new finite element technique for modelling stable crack growth; On the nature of crack propagation and arrest in a damaging material; A viscoplastic constitutive model for dynamic fracture; Crack tip parameters and temperature rise in dynamic crack propagation; Large deformations near a propagating crack tip; The influence of specimen boundary conditions on the fracture toughness of running cracks; An experimental and analytical investigation of axial crack propagation in long pipes; Stress fringe signatures for propagating cracks; Dynamic photoelastic investigation of two pressurized cracks approaching one another; Dynamic fracture mechanics with electromagnetic force and its application to fracture toughness testing; Fracture behavior under high rates of loading; Finite element modelling of dynamic cracking in wide plates; Short pulse fracture mechanics.
