Introduction of a New Dynamic Fracture Toughness Evaluation System

Introduction of a New Dynamic Fracture Toughness Evaluation System PDF Author: T. Kobayashi
Publisher:
ISBN:
Category : Absorbed energy
Languages : en
Pages : 9

Get Book Here

Book Description
Instrumented Charpy impact test has been widely used as a simple method for semi-empirically evaluating material impact toughness. The authors have developed a new instrumented Charpy impact testing system, which is called CAI (Computer Aided instrumented Charpy Impact testing) system. Using the CAI system, dynamic fracture toughness parameters such as Kd, Jd, Tmat, and various absorbed energies can be obtained from the load-deflection curve of a single precracked specimen for both ductile and brittle materials. It has been already put into practical use in Japan. This paper introduces the details of the toughness evaluation procedures in the CAI system.

Introduction of a New Dynamic Fracture Toughness Evaluation System

Introduction of a New Dynamic Fracture Toughness Evaluation System PDF Author: T. Kobayashi
Publisher:
ISBN:
Category : Absorbed energy
Languages : en
Pages : 9

Get Book Here

Book Description
Instrumented Charpy impact test has been widely used as a simple method for semi-empirically evaluating material impact toughness. The authors have developed a new instrumented Charpy impact testing system, which is called CAI (Computer Aided instrumented Charpy Impact testing) system. Using the CAI system, dynamic fracture toughness parameters such as Kd, Jd, Tmat, and various absorbed energies can be obtained from the load-deflection curve of a single precracked specimen for both ductile and brittle materials. It has been already put into practical use in Japan. This paper introduces the details of the toughness evaluation procedures in the CAI system.

Dynamic Fracture Toughness Evaluation by Measurement of CTOD (Crack Tip Opening Displacement).

Dynamic Fracture Toughness Evaluation by Measurement of CTOD (Crack Tip Opening Displacement). PDF Author: William N Sharpe (Jr)
Publisher:
ISBN:
Category : Materials
Languages : en
Pages : 88

Get Book Here

Book Description
Quantification of the dynamic fracture toughness of structural materials is essential to a wide range of problems - from nuclear accidents to ordnance applications. However, the difficulties associated with accurate measurements of cracks under dynamic loading are considerable. Thus there are no standardized procedures and few reliable results. This work describes a systematic study of the dynamic fracture toughness of SAE-01 tool steel, 4340 and HY100 steels and a tungsten, using the ISDG (Interferometric Strain/Displacement Gage) system which has very high frequency resolution. The major advantage of the method is that information is obtained very close to the crack tip, so that stress wave loading effects are accounted for. A detailed error analysis gives an uncertainty of -10% to +20% in the determination of fracture toughness, which compares with + or - 20% for published work.

Dynamic Fracture Mechanics

Dynamic Fracture Mechanics PDF Author: Arun Shukla
Publisher: World Scientific
ISBN: 9812773320
Category : Technology & Engineering
Languages : en
Pages : 374

Get Book Here

Book Description
Covering a wide variety of topics in dynamic fracture mechanics, this volume presents state-of-the-art experimental techniques and theoretical analysis on dynamic fracture in standard and exotic materials. Written by world renowned researchers, this valuable compendium contains eleven chapters on crack initiation, crack propagation, crack arrest, crack-stress wave interactions, and experimental, analytical and numerical methods in dynamic fracture mechanics. Contents: Modeling Dynamic Fracture Using Large-Scale Atomistic Simulations (H-J Gao & M J Buehler); Dynamic Crack Initiation Toughness (D Rittel); The Dynamics of Rapidly Moving Tensile Cracks in Brittle Amorphous Material (J Fineberg); Optical Methods for Dynamic Fracture Mechanics (H V Tippur); On the Use of Strain Gages in Dynamic Fracture (V Parameswaran & A Shukla); Dynamic and Crack Arrest Fracture Toughness (R E Link & R Chona); Dynamic Fracture in Graded Materials (A Shukla & N Jain); Dynamic Fracture Initiation Toughness at Elevated Temperatures with Application to the New Generation of Titanium Aluminides Alloys (M Shazly et al.); Dynamic Fracture of Nanocomposite Materials (A Shukla et al.). Readership: Researchers, practitioners, and graduate students in fracture mechanics and materials science.

Local Approach to Dynamic Fracture Toughness Evaluation

Local Approach to Dynamic Fracture Toughness Evaluation PDF Author: T. Ochiai
Publisher:
ISBN:
Category : Brittle fracture
Languages : en
Pages : 34

Get Book Here

Book Description
Fracture toughness properties of structural steels of 490-MPa strength class and weld metals under dynamic loading are studied in the light of the near crack tip stress fields. The loading rate in toughness tests range from 0.1 to 500 mm/s. The near-tip stress fields are analyzed by 3D-FEM considering the strain rate effect on the flow properties of materials. Temperature rise caused by high-speed plastic deformation is also included in the FE analysis. The critical CTOD at brittle fracture initiation decreases when increasing the loading rate. This is due to the elevation of a local stress near the crack tip. The local approach is applied to the dynamic fracture toughness evaluation. It is shown that the brittle fracture resistance evaluated in terms of the Weibull stress, an integrated stress over a highly stressed region near the crack tip, is a material property independent of the loading rate. Based on the Weibull stress fracture criterion, the dynamic fracture toughness can be predicted from static toughness results. An engineering procedure to estimate the loading rate effect on the fracture toughness is also presented.

Dynamic Fracture

Dynamic Fracture PDF Author: K. Ravi-Chandar
Publisher: Elsevier
ISBN: 0080472559
Category : Science
Languages : en
Pages : 265

Get Book Here

Book Description
Dynamic fracture in solids has attracted much attention for over a century from engineers as well as physicists due both to its technological interest and to inherent scientific curiosity. Rapidly applied loads are encountered in a number of technical applications. In some cases such loads might be applied deliberately, as for example in problems of blasting, mining, and comminution or fragmentation; in other cases, such dynamic loads might arise from accidental conditions. Regardless of the origin of the rapid loading, it is necessary to understand the mechanisms and mechanics of fracture under dynamic loading conditions in order to design suitable procedures for assessing the susceptibility to fracture. Quite apart from its repercussions in the area of structural integrity, fundamental scientific curiosity has continued to play a large role in engendering interest in dynamic fracture problems In-depth coverage of the mechanics, experimental methods, practical applications Summary of material response of different materials Discussion of unresolved issues in dynamic fracture

Dynamic Fracture Toughness: Papers

Dynamic Fracture Toughness: Papers PDF Author: Welding Institute
Publisher:
ISBN:
Category : Fracture mechanics
Languages : en
Pages : 364

Get Book Here

Book Description


Mechanics and Mechanisms of Fracture

Mechanics and Mechanisms of Fracture PDF Author: Alan F. Liu
Publisher: ASM International
ISBN: 1615032525
Category : Technology & Engineering
Languages : en
Pages : 452

Get Book Here

Book Description


Evaluation of Current Procedures for Dynamic Fracture-Toughness Testing

Evaluation of Current Procedures for Dynamic Fracture-Toughness Testing PDF Author: WL. Server
Publisher:
ISBN:
Category : Crack propagation
Languages : en
Pages : 16

Get Book Here

Book Description
Instrumented impact test requirements for impact velocity, inertial loading, time to fracture, and frequency response were developed as a part of a large testing program sponsored by the Electric Power Research Institute (EPRI). These test procedures relied heavily on current ASTM standards plus the composite experience of investigators throughout the world. This paper provides experimental verification of the EPRI developed procedures and clarifies some of the empirical relationships used in the procedures. The material investigated was a 4340 steel (Rc52) which was relatively insensitive to loading rate. Load-time information obtained simultaneously from an instrumented tup and strain-gaged specimen was analyzed for tests performed at various impact velocities. The results indicate that the EPRI developed procedures are conservative and allow reliable fracture-toughness measurements to be made.

Deformation and Fracture Behaviour of Polymers

Deformation and Fracture Behaviour of Polymers PDF Author: Wolfgang Grellmann
Publisher: Springer Science & Business Media
ISBN: 3662045567
Category : Technology & Engineering
Languages : en
Pages : 617

Get Book Here

Book Description
This book gives an overview of recent advances in the fracture mechanics of polymers, morphology property correlations, hybrid methods for polymer testing and polymer diagnostics, and biocompatible materials and medical prostheses, as well as application examples and limits.

From Charpy to Present Impact Testing

From Charpy to Present Impact Testing PDF Author: D. Francois
Publisher: Elsevier
ISBN: 008052897X
Category : Technology & Engineering
Languages : en
Pages : 497

Get Book Here

Book Description
From Charpy to Present Impact Testing contains 52 peer-reviewed papers selected from those presented at the Charpy Centenary Conference held in Poitiers, France, 2-5 October 2001. The name of Charpy remains associated with impact testing on notched specimens. At a time when many steam engines exploded, engineers were preoccupied with studying the resistance of steels to impact loading. The Charpy test has provided invaluable indications on the impact properties of materials. It revealed the brittle ductile transition of ferritic steels. The Charpy test is able to provide more quantitative results by instrumenting the striker, which allows the evolution of the applied load during the impact to be determined. The Charpy test is of great importance to evaluate the embrittlement of steels by irradiation in nuclear reactors. Progress in computer programming has allowed for a computer model of the test to be developed; a difficult task in view of its dynamic, three dimensional, adiabatic nature. Together with precise observations of the processes of fracture, this opens the possibility of transferring quantitatively the results of Charpy tests to real components. This test has also been extended to materials other than steels, and is also frequently used to test polymeric materials. Thus the Charpy test is a tool of great importance and is still at the root of a number of investigations; this is the reason why it was felt that the centenary of the Charpy test had to be celebrated. The Société Française de Métallurgie et de Matériaux decided to organise an international conference which was put under the auspices of the European Society for the Integrity of Structures (ESIS). This Charpy Centenary Conference (CCC 2001) was held in Poitiers, at Futuroscope in October 2001. More than 150 participants from 17 countries took part in the discussions and about one hundred presentations were given. An exhibition of equipment showed, not only present day testing machines, but also one of the first Charpy pendulums, brought all the way from Imperial College in London. From Charpy to Present Impact Testing puts together a number of significant contributions. They are classified into 6 headings: •Keynote lectures,•Micromechanisms,•Polymers,•Testing procedures,•Applications,•Modelling.