Damage Assessment Of Materials Research Articles

The Legal Consequences of a Violation: Reparation/Just Satisfaction/Damages by Human Rights Bodies and Investment Tribunals

Abstract Remedies granted by both human rights courts and investment tribunals are generally based on the international law of state responsibility as codified by the International Law Commission (ILC) in 2001. However, some special rules (leges speciales) do exist in the statutes of human rights courts and in a few international investment agreements. Despite the different scopes of protection of the two areas of international law, there are remarkable similarities in judicial practice, yet important differences remain. This article explores to what extent there is already mutual influence in practice and where there is still room for mutual inspiration. It comes to the conclusion that investment tribunals could take more into consideration that victims may suffer damage, in particular non-material damage, by the mere violation of their rights. Conversely, human rights courts could pay closer attention to economic valuation criteria when it comes to the assessment of material damage.

Mechanochemical Reactivity of a 1,2,4-Triazoline-3,5-dione-Anthracene Diels-Alder Adduct.

Force-responsive molecules that produce fluorescent moieties under stress provide a means for stress-sensing and material damage assessment. In this work, we report a mechanophore based on Diels-Alder adduct TAD-An of 4,4'-(4,4'-diphenylmethylene)-bis-(1,2,4-triazoline-3,5-dione) and initiator-substituted anthracene that can undergo retro-Diels-Alder (rDA) reaction by pulsed ultrasonication and compressive activation in bulk materials. The influence of having C-N versus C-C bonds at the sites of bond scission is elucidated by comparing the relative mechanical strength of TAD-An to another Diels-Alder adduct MAL-An obtained from maleimide and anthracene. The susceptibility to undergo rDa reaction correlates well with bond energy, such that C-N bond containing TAD-An degrades faster C-C bond containing MAL-An because C-N bond is weaker than C-C bond. Specifically, the results from polymer degradation kinetics under pulsed ultrasonication shows that polymer containing TAD-An has a rate constant of 1.59×10-5 min-1 , while MAL-An (C-C bond) has a rate constant of 1.40×10-5 min-1 . Incorporation of TAD-An in a crosslinked polymer network demonstrates the feasibility to utilize TAD-An as an alternative force-responsive probe to visualize mechanical damage where fluorescence can be "turned-on" due to force-accelerated retro-Diels-Alder reaction.

SPECTRAL-ACOUSTIC MONITORING OF DAMAGE IN POLYCRYSTALLINE MATERIALS BASED ON A SIMULATION-MECHANICAL MODEL

In this study, a modified simulation-mechanical model is developed for dispersed damage accumulation in a polycrystalline material based on continuum damage mechanics and physical mesomechanics. The main damaging factors are assumed to be the field of dispersed microcracks in the material and the field of internal stresses arising primarily from linear structural defects. The statistical limit state criterion of a material following from the proposed model is consistent with the known information about the failure conditions of brittle and ductile structural materials. The possible application of the limit state criterion is discussed for typical cases of failure and transition from elastic to elastic-plastic deformation of polycrystalline structural materials. The proposed spectral-acoustic method for material damage assessment is used to analyze elastic pulse propagation in the simulated medium. The existence of some acoustic effects in the damaged medium is substantiated, which can be useful for the instrumental assessment of material damage at any time during loading of a sample or service of a structural element. It is shown that the spectral-acoustic method can provide a basis for a technique of measuring the damage parameters included in the proposed model. Available experimental data confirm the correctness of the damage assessment approach for structural materials. Further experimental studies will develop methods for express monitoring of dispersed damage in metal structures subjected to thermomechanical loads.

Виктимизация населения современной России. Девиантологический взгляд

Abstract: In modern Russia many people become victims of crimes every day. Insufficient adaptation of Russians to ensure personal security is caused by their personal criminal vulnerability (victimization). The victimological situation in the country, without exaggeration, can be assessed as extremely tense, revealing the need to create a system of measures to ensure the proper security of citizens and legal entities. The solution of this problem is impossible without a deep study of the real state of victimization of the population. On the basis of official criminal statistics, the authors present the dynamics, state, structure of the negative consequences of crime. The assessment of material damage from crimes committed in the country is given. The specificity of arrays of victims of crimes in transport is shown in comparison with the general array of victims of crimes. The geography of criminal victimization is reflected. The nature of latent victimization is investigated. The ratio of criminal victims among legal entities and individuals is considered. The results of the proposed analysis of criminal victimization of the population will make it possible to make management decisions aimed at effective fighting crime.

Direct Evaluation of the Stress Intensity Factors for the Single and Multiple Crack Problems Using the P-Version Finite Element Method and Contour Integral Method

Stress intensity factor (SIF) is one of three important parameters in classical linear elastic fracture mechanics (LEFM). The evaluation of SIFs is of great significance in the field of engineering structural and material damage assessment, such as aerospace engineering and automobile industry, etc. In this paper, the SIFs of a central straight crack plate, a slanted single-edge cracked plate under end shearing, the offset double-edge cracks rectangular plate, a branched crack in an infinite plate and a crucifix crack in a square plate under bi-axial tension are extracted by using the p-version finite element method (P-FEM) and contour integral method (CIM). The above single- and multiple-crack problems were investigated, numerical results were compared and analyzed with results using other numerical methods in the literature such as the numerical manifold method (NMM), improved approach using the finite element method, particular weight function method and exponential matrix method (EMM). The effectiveness and accuracy of the present method are verified.

Procedure and Instruments for the Material Damage Assessment by the LM-Hardness Method on the In-Service Scratching of Structure Element Surfaces

The procedure for the material damage assessment by the LM-hardness method, consisting of the in-service scratching of structure element surfaces and employing portable instruments for its implementation, is described. These instruments can provide the rapid analysis of damage of a structural element to be diagnosed, continuous measurement of axial displacements of the embedded scratching tip, moving over the surface of this element, systematization, and statistical processing of experimental data for Weibull homogeneity coefficient computations. The latter results derived via the LM-hardness method are used to assess the damage rate of the material. The advantage of these instruments is their high accuracy and performance in measuring a large number of axial displacements of the tip necessary for statistical processing as well as actual testing on vertical, ceiling, and inclined surfaces of structural elements.

Fatigue crack analysis of ferrite material by acoustic emission technique

Recently in various fields, numerous researches are going on for the assessment of material damage on the basis of crack initiation and propagation. Various methods are available in NDT for this purpose, among which analysis using released acoustic emission (AE) waves due to crack propagation is very effective due to its dynamic monitoring features. Various approaches are proposed for long time to make it an ideal method for accurate monitoring of crack behaviors in materials. In fragmentation theory there are some proportionality among the relations of AE event, AE energy, area and volume of cracks etc., which are calculated from the released AE waves from any dynamic crack. It has been found that the necessity of calculating the fractal dimension is important in verifying these relationships. This parameter is emphasized for determining the geometry of the irregularity in crack surface and crack volume. In this paper a novel approach based on image processing is proposed to find out the fractal dimension for analyzing the crack propagation characteristics. Finally, the proportionality relationships of AE parameters with crack propagation behavior in ferrite cast iron under fatigue loading are demonstrated experimentally.

EBSD法によるクリープ損傷評価のためのラウンドロビン試験

Crystal orientations of creep damaged Type 316 stainless steel (SUS316L) were measured by 3 organizations using the same specimens, passed in a round robin, in order to investigate the scatter in material damage assessment using the electron backscatter diffraction (EBSD) technique. Two misorientation parameters, KAM (Kernel average misorientation) and GOS (Grain orientation spread), were calculated using mapping data of measured crystal orientations. It was shown that KAM and GOS correlated well with the degree of creep strain. However the scatter in GOS was smaller than in KAM. The GOS parameter showed an excellent correlation with both of the creep strain and creep damage ratio. It was concluded that the GOS parameter can be used for evaluation of the creep damage. The empirical relationship between GOS parameter and the degree of the creep damage can be shared regardless of the SEM/EBSD system used.

Carbon nanotube film interlayer for strain and damage sensing in composites during dynamic compressive loading

A major challenge in the damage assessment of materials under dynamic, high strain rate loading lies in the inability to apply most health monitoring methodologies to the analysis and evaluation of damage incurred on short timescales. Here, we present a resistance-based sensing method utilizing an electrically conductive carbon nanotube film in a fiberglass/vinyl ester composite. This method reveals that applied strain and damage in the form of matrix cracking and delamination give rise to electrical resistance increases across the composite specimen; these can be measured in real-time during high strain rate loading. Damage within the composite specimens is confirmed through pre- and post-mortem x-ray micro computed tomography imaging.

Application of the surface and volumetric positron techniques for the assessment of material damage in operational conditions

AbstractPositron Systems, Inc. applies surface and volumetric positron techniques to investigate damage in metal components in operational conditions. The width and shape of Doppler Broadening gamma peak (S‐parameter) is used for defect analysis. Two techniques are commonly used: the Induced Positron Analysis ‐ Surface technique (IPA‐S) to investigate a surface and near‐surface effects and the Induced Positron Analysis‐ Volumetric technique (IPA‐V) that penetrates through the volume of the examined materials. Positron Annihilation measurements have been successfully performed in many applications. Presented below are cases demonstrating successful applications in assessing damage in gas generator fuel injector stems, aerospace parts that underwent strain and fatigue treatment, and residual stress effects in shot‐peened specimens and steel plates with cracks. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Assessment of material damage in a nickel-base superalloy using nonlinear Rayleigh surface waves

A reliable laser-based ultrasonic technique is developed to measure the second order harmonic amplitude of a Rayleigh surface wave propagating in metallic specimens. Rayleigh waves are experimentally generated with a wedge transducer and detected with a heterodyne laser interferometer. The capability of this system to measure the nonlinear contribution present in Rayleigh surface waves is demonstrated, and these results are interpreted in terms of a parameter developed for Rayleigh surface waves which corresponds to the nonlinear parameter of a longitudinal wave, β. The proposed measurement technique is used to assess damage in nickel-base high temperature alloy specimens, and the evolution of material nonlinearity under various loading conditions is quantitatively measured in terms of the increasing amplitude of the second order harmonic. These results show that there is a significant increase in the second order harmonic amplitude at monotonic tensile loads above the material’s yield stress, and that during low cycle fatigue tests, the increase in the second order harmonic amplitude is considerable, although less significant than that in the monotonic loading case. The results from this study show the major role that accumulated plasticity plays in the increase in material nonlinearity, and demonstrate the effectiveness of the proposed experimental procedure to track damage in high temperature alloys.

Fusion Plant Material Damage Due to Neutron Irradiation: An Assessment for ITER In-Vessel Components

This paper summarises and discusses the results of the material damage assessment for the in-vessel components of the International Tokamak Experimental Reactor (ITER), with reference to the baseline design defined in the Interim Design Report 95 (IDR 95) by the ITER Joint Central Team (JCT). Dpa has been calculated for various zones of the First Wall (FW) and of the Shield Blanket (SB), where stainless steel is located. The second damage exposure index that has been considered and estimated is the gas production into the various ITER zones. 12 refs., 1 fig., 4 tabs.

A methodology for the economic assessment of material damage caused by SO2 and NOx emissions in Europe

Damage to materials causes high economic losses in Europe. A large part of this damage can be attributed to the emissions caused by the energy and the transport sector. In the paper, the procedure for the economic assessment of material damages caused by SO2 and NOx emissions in Europe is described. Model and data requirements are outlined, and gaps and uncertainties of the quantification are discussed. Two types of results are presented: First, the marginal (additional) costs of damage to materials caused by an additional power plant are assessed. The analysis covers plants with different technologies. Results for the fossil power plants are in the range of 0.0062 to 0.12 mECU/kWh. In addition, the total economic material damage due to the present air pollution was assessed. It is in the range of 2.9 to 5.3 × 109 ECU/year. However, the analysis has many uncertainties. Most noteworthy are the material inventories and partially the damage functions and input data.

Assessing the defect-free structure

There has been a strong incentive within Nuclear Electric to develop a comprehensive assessment procedure to evaluate the high temperature response of structures; the so-called R5 procedure is extensive and Vols. 2 and 3 deal with the analytical approach and the assessment of creep fatigue damage for defect-free structures. In this paper we describe the approach which has been adopted and identify the relationship between the analytical requirement and material damage assessment under cyclic loading.

Assessing the defect-free structure

Abstract There has been a strong incentive within Nuclear Electric to develop a comprehensive assessment procedure to evaluate the high temperature response of structures; the so-called R5 procedure is extensive and Vols. 2 and 3 deal with the analytical approach and the assessment of creep fatigue damage for defect-free structures. In this paper we describe the approach which has been adopted and identify the relationship between the analytical requirement and material damage assessment under cyclic loading.