bluuebunny/crossref_metadata_2025 huggingface dataset:
Phase I Active Immunotherapy With Combination of Two Chimeric, Human Epidermal Growth Factor Receptor 2, B-Cell Epitopes Fused to a Promiscuous T-Cell Epitope in Patients With Metastatic and/or Recurrent Solid Tumors
Authors: Kaumaya Pravin T.P. , Foy Kevin Chu , Garrett Joan , Rawale Sharad V. , Vicari Daniele , Thurmond Jennifer M. , Lamb Tammy , Mani Aruna , Kane Yahaira , Balint Catherine R. , Chalupa Donald , Otterson Gregory A. , Shapiro Charles L. , Fowler Jeffrey M. , Grever Michael R. , Bekaii-Saab Tanios S. , Carson William E.
Published: September 2009

Purpose

To evaluate the maximum-tolerated dose (MTD), safety profile, and immunogenicity of two chimeric, B-cell epitopes derived from the human epidermal growth factor receptor (HER2) extracellular domain in a combination vaccine with a promiscuous T-cell epitope (ie, MVF) and nor-muramyl-dipeptide as adjuvant emulsified in SEPPIC ISA 720.

Patients and Methods

Eligible patients with metastatic and/or recurrent solid tumors received three inoculations on days 1, 22, and 43 at doses of total peptide that ranged from 0.5 to 3.0 mg. Immunogenicity was evaluated by enzyme-linked immunosorbent assay, flow cytometry, and HER2 signaling assays.

Results

Twenty-four patients received three inoculations at the intended dose levels, which elicited antibodies able to recognize native HER2 receptor and inhibited both the proliferation of HER2-expressing cell lines and phosphorylation of the HER2 protein. The MTD was determined to be the highest dose level of 3.0 mg of the combination vaccine. There was a significant increase from dose level 1 (0.5 mg) to dose level 4 (3.0 mg) in HER2-specific antibodies. Four patients (one each with adrenal, colon, ovarian, and squamous cell carcinoma of unknown primary) were judged to have stable disease; two patients (one each with endometrial and ovarian cancer) had partial responses; and 11 patients had progressive disease. Patients with stable disease received 6-month boosts, and one patient received a 20-month boost.

Conclusion

The combination vaccines were safe and effective in eliciting antibody responses in a subset of patients (62.5%) and were associated with no serious adverse events, autoimmune disease, or cardiotoxicity. There was preliminary evidence of clinical activity in several patients.
Venous Thromboembolism in the Hematologic Malignancies
Authors: Falanga Anna , Marchetti Marina
Published: September 2009

Patients with hematologic malignancies are at high risk of thrombotic or hemorrhagic complications. The incidence of these events is greatly variable and is influenced by many factors, including the type of disease, the type of chemotherapy, and the use of a central venous device. As in solid tumors, a number of clinical risk factors have been identified and contribute to the increasing thrombotic rate in hematologic malignancies. Biologic properties of the tumor cells can influence the hypercoagulable state of patients with these malignancies by several mechanisms. Of interest, oncogenes responsible for neoplastic transformation in leukemia also may be involved in clotting activation. Epidemiologic data allow an estimate of the incidence of venous thromboembolism (VTE) in acute leukemia, lymphomas, and multiple myeloma (MM). In this review, we focus on the epidemiology, pathogenesis, and VTE management in these three hematologic malignancies. No recommendation for routine thromboprophylaxis in these conditions, with the exception of MM, is available. Large, prospective, randomized clinical trials are needed to establish the best practice for thromboprophylaxis and treatment of VTE in these types of cancers.
Three Changes for Affordable Care: One Payer's Wish List
Authors: Newcomer Lee
Published: September 2009

The oncology cost trend is approximately two times higher than that of medicine overall. Patients with cancer once had amnesty in the cost debate, but this is no longer the case. How do we cut cost and still provide quality care?
Can Physicians Refuse Treatment to Patients Who Smoke?
Authors: Pawlik Timothy M. , Olver Ian N. , Storm Courtney D. , Rodriguez Maria Alma
Published: September 2009

Irrespective of the “rightness” of smoking behavior, physicians have a duty to offer all patients appropriate anticancer therapy and supportive care and to help their patients become tobacco free.
Service Provider Competition: Delay Cost Structure, Segmentation, and Cost Advantage
Authors: Afanasyev Maxim , Mendelson Haim
Published: September 2009

We model competition between two providers who serve delay-sensitive customers. We compare a generalized delay cost structure, where a customer's delay cost depends on her service valuation, with the traditional additive delay cost structure, where the delay cost is independent of the customer's service valuation. Under the additive delay cost structure, service providers offer different prices and expected delays, but customers are indifferent between the providers. Under the generalized delay cost structure, when the providers have different capacity or operating costs, we obtain value-based market segmentation, whereby higher-value customers choose one provider and lower-value customers choose the other. We study how the delay cost parameters, the market size, and the service providers' costs affect the structure of the equilibrium.
The Impact of Quick Response in Inventory-Based Competition
Authors: Caro Felipe , Martínez-de-Albéniz Victor
Published: September 2009

We propose an extension of the competitive newsvendor model to investigate the impact of quick response under competition. For this purpose, we consider two retailers that compete in terms of inventory: customers that face a stockout at their first-choice store will look for the product at the other store. Consequently, the total demand that each retailer faces depends on the competitor's inventory level. We allow for asymmetric reordering capabilities, and we are particularly interested in the case when one of the firms has a lower ordering cost but can only produce at the beginning of the selling season, whereas the second firm has higher costs but can replenish stock in a quick response manner, taking advantage of any incremental knowledge about demand (if it is available). We visualize this problem as the competition between a traditional make-to-stock retailer that builds up inventory before the season starts versus a retailer with a responsive supply chain that can react to early demand information. We provide conditions for this game to have a unique pure-strategy subgame-perfect equilibrium, which then allows us to perform numerical comparative statics. We confirm that quick response is more beneficial when demand uncertainty is higher or exhibits a higher correlation over time. We also find that the competitive advantage from quick response is larger when facing a slow response competitor, and interestingly, asymmetric competition can be desirable to both competitors.
Apparent subject-object inversion in Chinese
Authors: Her One-Soon
Published: September 2009

This article is concerned with the problem of argument-function mismatch observed in the (apparent) subject-object inversion in Chinese consumption verbs, e.g.,
Development, Verification, and Implementation of a National Full Consensus Fracture Toughness Test Method Standard for Advanced Ceramics
Authors: Jenkins MG , Salem JA , Quinn GD , Bar-On I
Published: September 2009

The dawn of a new age in understanding fracture of brittle material occurred in 1999 (eight years after an ASTM task group on fracture toughness of advanced ceramics was formed) when a national full consensus fracture toughness test method standard was approved as ASTM Test Methods for the Determination of Fracture Toughness of Advanced Ceramics at Ambient Temperature (C 1421 ). C 1421 uses common flexure test specimen geometries (typically 3 × 4 × 50 mm) in conjunction with three and fourpoint flexure test configurations. Three different types of notch/crack geometries are employed: single edge precracked beam (SEPB); surface crack in flexure (SCF); and chevron-notched beam (CNB). Extensive experimental, analytical, and numerical evaluations were conducted prior to and during the approval of the standard. Several round robins (e.g., VAMAS) verified and validated the choice of dimensions and test parameters. Two concurrent post-approval implementations of the standard are cited: i) fracture tests of a single composition of an advanced ceramic led to the introduction of a standard reference material (SRM) for fracture toughness and ii) fracture tests on two different compositions of a ceramic system showed the statistically significantly greater fracture toughness of one material for a wear application.
Fracture Toughness of Ceramics using the SEVNB Method: From a Preliminary Study to a Standard Test Method
Authors: Kübier JJ
Published: September 2009

Numerous methods are currently in use to measure the fracture toughness of ceramic materials. Methods based on widely accepted theory are often difficult to realize, unreliable, or expensive. Recently, the single-edge-V-notched beam (SEVNB) method, where a saw cut is tapered to a sharp V-notch using a razor blade sprinkled with diamond paste, was reintroduced. The fracture toughness was measured with this method on five advanced technical ceramics in an international round robin. It showed that the repeatability and reproducibility of this method was very good. Further, the method proved to be forgiving and robust with respect to notch preparation for ceramics having a major microstructural feature greater than about 1 μm in size. Most participants had no difficulties conducting the measurements and rated the SEVNB method as user-friendly, easy and cheap to conduct, reliable, accurate, and worthwhile for standardization. Therefore, a recommended practice has been written that is now serving as basis for a new CEN standard.
Fracture Testing of a Layered Functionally Graded Material
Authors: Hill MR , Carpenter RD , Paulino GH , Munir ZA , Gibeling JC
Published: September 2009

This paper describes measurements of the KI R-curve for a layered ceramicmetallic functionally graded material (FGM) composed of Ti and TiB phases. Single edge notch bend specimens were fabricated for crack propagation perpendicular to the graded layers from the brittle to the ductile side of the FGM. The precracking method and residual stresses affected the measured toughness. A new reverse bending method produced a sharp precrack without damaging the material. A representative sample indicates R-curve behavior rising from Kmeas = 7 MPa∙m1/2 in the initial crack-tip location (38% Ti and 62% TiB) to 31 MPa∙m1/2 in pure Ti. Residual stresses acting normal to the crack-plane were measured in the parent plate using the crack compliance technique. The residual stress intensity factor in the SE(B) specimen determined from the weight function was -2.4 MPa∙m1/2 at the initial precrack length. Thus, the actual material toughness at the start of the test was 34% less than the measured value.
Water Potential Response in Fractured Basalt from Infiltration Events
Authors: Hubbell JM , Mattson ED , Sisson JB , McElroy DL
Published: September 2009

The detection of moisture movement in the vadose zone beneath hazardous waste disposal sites is important for monitoring and predicting contaminant transport in the subsurface. This study was conducted to determine if moisture movement could be detected from natural water infiltration in a dual porosity, fractured basalt at the Idaho National Engineering and Environmental Laboratory (INEEL). Episodic infiltration events were determined by examining long-term water potential over three and a half years. Water potential measurements were collected from 2 to over 30 m below land surface. Instruments were placed in both fractured and unfractured basalt media. Water potential measurements were within the tensiometric range, from approximately +100 to −250 cm of water. Typically, water potentials within the fractured basalt exhibited a near steady-state unit-gradient downward flux. However, episodic snowmelt infiltration events at land surface produced detectable changes in water potentials at depths to 15.5 m, in some cases within a few days of the infiltration events. Smaller infiltration events were difficult to distinguish due to fluctuations in water potential resulting from changes in barometric pressure. Water potential responses in boreholes varied both temporally and spatially during episodic infiltration events indicating preferential flow pathways through the fractured basalt. The results of this study indicate that water potential measurements can be used to detect and monitor deep infiltration events at waste disposal sites using tensiometers.
Pressure-Pulse Test for Field Hydraulic Conductivity of Soils: Is the Common Interpretation Method Adequate?
Authors: Chapuis RP , Cazaux D
Published: September 2009

Pressure-pulse tests are performed in boreholes in either impervious rock or clayey formations. According to the usual theory, they give the hydraulic conductivity, k, and the storativity, S, of the tested material. However, comparative testing programs have shown that the usual interpretation method may give k values that are quite different from those given by other methods. It gives also unrepresentative (much too low) values of S for the tested formations. Several reasons for the discrepancies are examined. First, the theory came from a heat conduction problem but the mass and energy transfers in a pulse test are quite different from those in the heat conduction problem. Thus the usual interpretation method is derived from equations that do not represent correctly the physical phenomena involved in a pulse test. A correct theory should use equations that consider medium deformation to be partly instantaneous (undrained) and partly delayed (drained) during and after the pulse. This is not the case in the commonly used theory. It should also consider that both the testing system and the formation wall are deformed during the pulse, which is ignored by the usual theory. Besides this theoretical inadequacy, the usual interpretation method is frequently affected by an inaccurate knowledge of the local piezometric level for the test. This level is frequently guessed prior to testing, and this estimate may be incorrect. However, a velocity graph technique can be used to analyze the test data and establish the real piezometric level for the test. Considering the inadequacy of the usual equations and interpretation method, it is proposed to interpret the test data as those of a slug test after having determined the local piezometric level using the velocity graph method. Hvorslev's method is used after introducing an imaginary open tube with an inside diameter that is defined by the volume of injected water associated with the initial pulse. A detailed example is treated where this interpretation method yielded a k-value close to that obtained from a constant-head test in the same injection cavity, both values being 50 times lower than the k-value derived from the usual superposition method.
Impact of Residual NAPL on Water Flow and Heavy Metal Transfer in a Multimodal Grain Size Soil under Saturation Conditions: Implications for Contaminant Mobility
Authors: Galvez-Cloutier R , Dubé J-S
Published: September 2009

This paper presents the study of the influence of residual NAPL on the transport of various heavy metals trough a mixed contaminated soil under saturation conditions. The concepts of soil structure, preferential flow, heavy metal transfer: retention and transport and multiphase hydrodynamics are investigated for various conditions. Residual NAPL causes water to bypass regions it occupies towards regions having less flow resistance, hence creating preferential flow and transport. Residual NAPL can also obstruct small pore entries and mask active surface sites. Thus, it can influence heavy metal net transfer. Our results show that mobility of heavy metals is altered by the presence of NAPL. This behavior has important implications from both contamination assessment and remediation perspectives.
Philosophies for Assessing Durability of Commercial and Infrastructure Composite Systems
Authors: Case SW , Reifsnider KL , Lesko JJ
Published: September 2009

A key need for the commercial acceptance and viability of composite structural material systems is a methodology for reliability and lifetime predictions. In this paper, we present a philosophy in which the residual strength of the composite material is calculated as a function of applied loading conditions, environment, and resulting failure mode. Two specific example applications are considered: the assessed and verified performance of fiber wound composite tubes and pultruded shapes. We attempt to demonstrate the understanding of the controlling damage mechanisms and the degradation processes that contribute to the loss in stiffness and strength under simulated service conditions.
The Effect of Moisture, Matrix and Ply Orientation on Delamination Resistance, Failure Criteria and Fracture Morphology in CFRP
Authors: Greenhalgh ES , Singh S
Published: September 2009

The objective of this work was to relate damage mechanisms, gleaned through electron microscopy, to delamination loci generated using fracture toughness (Mixed-Mode Bend) tests. From this, mixed-mode criteria were ranked using the ϰ2 method (goodness of fit). The shapes of the failure loci (GT versus %GI) were related to the damage mechanisms, and to the moisture content, fibre type and ply orientation. Due to cusp formation, the delamination toughness increased as the proportion of Mode II increased. A further finding was that a ‘hump’ which was observed in the failure loci under Mode I dominated loading was due to fibre bridging. Ply orientation also had a significant effect on the toughness; 0°/90° interface was about 45% tougher than the 0°/0° interface due to secondary matrix cracking parallel to the crack front. The presence of such additional mechanisms indicates that delamination toughness is not a material property but is dependent on ply orientation.
Interlaminar Crack Propagation in CFRP: Effects of Temperature and Loading Conditions on Fracture Morphology and Toughness
Authors: Sjögren A , Asp LE , Greenhalgh ES , Hiley MJ
Published: September 2009

This paper presents a survey of fractographic features associated with interlaminar failure of HTA/6376C carbon fiber/epoxy laminates. The interlaminar toughness and fracture morphology are investigated for effects of fatigue and static loading at elevated temperatures. In particular, Mode II loading conditions are investigated. Special emphasis is on initiation of matrix rollers and striations, two features indicative of Mode II fatigue failure. The initial mechanisms for delamination in this material under static and fatigue loading were found to be the same; the development of angled cracks ahead of the crack front, initiating from the fiber/matrix interface. Subsequent growth of the delamination was dependant on the loading conditions; under static loading shear cusps developed and coalesced whilst under cyclic loading increased plasticity led to development of matrix rollers. Fatigue striations observed in the fiber imprints were also found to initiate from the fiber/matrix interface cracks. The morphology of the striations, however, depended on the magnitude of the fatigue loading.
Validation of Miniature Fracture Toughness Specimens for Material Surveillance
Authors: Valo M , Planman T , Wallin K , Rintamaa R , Ahlstrand R , Kohopää J
Published: September 2009

Fracture toughness testing in the elastic-plastic temperature range of material behavior is described in the Master Curve standard ASTM 1921-97. The standard allows measurement of valid fracture toughness values up to KJC= 100 MPa√m with clearly smaller than standard CVN-size specimens for the irradiated material condition. However, a relatively small amount of data measured with miniature specimens of cross-sections 5 mm × 5 mm or 3 mm × 4 mm have been published and hence the utilization of such small specimens is generally not accepted even if the universal specimen size criteria are fulfilled. In this study, the fracture toughness transition temperature T0 has been measured for a high phosphorus content WWER 440 weld coded as W502 both in the non-irradiated and in the irradiated and annealed material conditions. Three-point bend specimens of cross-sections 10 mm × 10 mm, 5 mm × 5 mm and 3 mm × 4mm were used in the study.
Examination on Fracture Resistance of F82H Steel and Performance of Small Specimens in Transition and Ductile Regimes
Authors: Wallin K , Laukkanen A , Tähtinen S
Published: September 2009

Fracture toughness determination standards and procedures give limits for the measuring capacity of different specimen sizes and types. Numerical methods and local approach are used as additional means to determine the validity of the toughness estimates and provide toughness scaling criteria for integrity assessment. The current study contributes to this domain and presents experimental and numerical results of fracture toughness and tearing resistance of F82H ferritic stainless steel. Three-point bend specimens of sizes 3 × 4 × 27 mm, 5 × 5 × 27 mm, 5 × 10 × 55 mm, 10 × 10 × 55 mm and 25 mm compact tension specimens are tested in the temperature range of-196°C to room temperature, in order to determine and characterize the fracture properties of F82H and specimen measuring capabilities from brittle lower shelf cleavage to upper shelf ductile R-curve. The experimental results are used to calibrate local approach models, which are then further applied to determine the attributes and usability of the different small specimens.
A Study of Specimen Size Effects on the Initiation Toughness and Tearing Resistance of an A533B-1 Steel
Authors: Wardle G
Published: September 2009

This paper provides comparison of initiation toughness values and JR curve data for a series of geometrically scaled compact (CT) and single edge notched bend (SENB) geometry specimens taken from a well characterized A533B-1 pressure vessel steel. The CT specimens (W = 2B) were of thickness B = 100, 40, 20, 15, 12.5 & 10 mm, and SENB specimens (W = 2B and W = B) of B = 20, 10 & 5 mm. The data reported are multi-specimen J-Δa values obtained from a total in excess of 400 tests made at ambient temperature (20°C) and 288°C on both plain-sided and sidegrooved specimens. The findings of the work indicate that for the material under study there is little effect of specimen size or geometry on the initiation toughness for a given level of sidegrooving. It also indicates that small size specimens (i.e., W = 10, B = 5mm) can provide JR curve data equivalent to those obtained for the larger specimens for levels of J up to 600kJm-2 and crack extension Δa up to approximately 25% of their initial remaining ligament (40% for 20% side grooved specimens). Suggestions are made to relax the current specimen size validity limits. The results presented here encourage the use of SENB specimens possibly as small as 5 × 5 mm for the determination of initiation toughness in these materials
Finite Element Simulations and Empirical Correlation for Charpy-V and Subsize Charpy Tests on an Unirradiated Low-Alloy RPV Ferritic Steel
Authors: Catherine CS , Poussard C , Vodinh J , Schill R , Hourdequin N , Forget P , Galon P
Published: September 2009

Charpy-V test results are widely used for the surveillance program of RPV (Reactor Pressure Vessel) embrittlement by neutron irradiation. Service life extension of nuclear power plants and more stringent safety requirements are increasing the request for small test specimens such as subsize Charpy. Furthermore, the empirical correlation formulas between conventional Charpy-V and fracture toughness are often questionable. Therefore, prior to use of reduced size specimens, different hypotheses have to be validated and this can only be achieved by combining tests and finite element simulations. The material of interest is a nuclear RPV low alloy ferritic steel 16MND5 (eq. A508 C13). Instrumented impact tests were performed on Charpy-V and subsize Charpy over a wide range of temperatures. The hyperbolic tangent curve from W. Oldfield [1] was fitted to the results. Then, correlation formulas are evaluated and commented.

In a first step, the aim of the finite element simulations is to get a clear description of the global mechanical behavior of the specimens. A complete description of dynamic impact tests is not required for fracture mechanics purposes. A quasi-static simulation taking into account strain rate effect on the material response is sufficient. However, a 3D analysis is required even for cleavage failure mode. The second step is related to the transferability of fracture criteria. This task has been initiated at low temperatures using the Beremin cleavage model [2] and in the ductile regime using the Rousselier porous model [3]. The finite element results are compared to the experimental one. These results show good transferability potential.
Correlation Between Subsize and Full-size Charpy Impact Properties of Neutron-Irradiated Reactor Pressure Vessel Steels
Authors: Dohi K , Soneda N , Onchi T , Matsui H
Published: September 2009

The correlation between subsize and full-size Charpy impact properties of reactor pressure vessel steels have been investigated using 1/3 and 1/4 subsize specimens cut from the broken halves of full-size specimens irradiated to 2.7 × 1023 n m-2 (E>lMeV) at 288 °C. We found that ductile-to-brittle transition temperature (DBTT) and upper shelf energy (USE) of subsize specimens have good correlation with those of full- size specimens irrespective of steel types and irradiation conditions, and the shift in the DBTT due to irradiation embrittlement is independent of specimen size. In addition, 1/4 size Charpy data have more scatter than 1/3 size data. Based on the results, we propose a new method to correlate the absorbed energy curve obtained by the subsize test with that by the full-size test. This correlation method is capable to predict adjusted reference temperatures and USEs used in surveillance test programs.
Application of the Reconstituted Subsize Specimens for Assessment of Irradiation Embrittlement of RPV Steels
Authors: Korolev YN , Shtrombakh YI , Nikolaev YA , Krasikov YA , Platonov PA
Published: September 2009

The actual values of the weld metal characteristics required for determination of the RPV lifetime, that is the ductile-to-brittle transition temperature (DBTT) in the unirradiated condition (Tk0), the phosphorus and copper contents (that are known to affect the radiation stability of steel), were not measured during manufacturing of old VVER-440 reactors. The small samples (templets) were cut out of the inside surface of the old Russian VVER-440 reactor pressure vessels (RPV) to assess the actual condition of the RPV material before and after post-irradiation annealing and after re-irradiation. Calculations have shown that it is not admissible to cut out samples of the size appropriate for machining of fullsize Charpy specimens necessary to comply with Russian Guide for determination of RPV steel DBTT. An application of subsize specimens for estimation of irradiation embrittlement of RPV steel was substantiated. In order to substantiate application of reconstituted subsize specimens made from broken subsize specimens for assessment of irradiation embrittlement of RPV materials, the correlation dependencies between the DBTT values of reconstituted and standard subsize specimens were developed. With this aim reconstitution of broken 5×5×27.5 mm specimens was performed by the stud-welding method. Both unirradiated and irradiated to high fluence steels were used in this program. The influence of reconstitution on the correlation dependence of DBTT for standard fullsize and subsize impact specimens was studied. Irradiation and re-irradiation kinetics of RPV steels were studied using subsize specimens machined from templets of operating units.
Evaluation of Fatigue Properties with Miniature Hourglass Specimen
Authors: Hirose T , Suzuki T , Tanigawa H , Ando M , Kohyama A , Katoh Y , Narui M
Published: September 2009

In fusion applications, the structural materials will be exposed to cyclic stress caused by temperature cycling from reactor operation. Thus it has been recognized that the investigation of fatigue properties under fusion reactor conditions is essential to reactor design. The objectives of this work are to establish fatigue test techniques for irradiated specimens and to investigate the effect of cyclic deformation on the microstructure of reduced activation ferritic/martensitic steels, RAFs.
Mechanical Property Testing of Irradiated Zircaloy Cladding Under Reactor Transient Conditions
Authors: Daum RS , Majumda S , Tsai H , Bray TS , Koss DA , Motta AT , Billone MC
Published: September 2009

Specimen geometries have been developed to determine the mechanical properties of irradiated Zircaloy cladding subjected to the mechanical conditions and temperatures associated with reactivity-initiated accidents (RIA) and loss-of-coolant accidents (LOCA). Miniature ring-stretch specimens were designed to induce both uniaxial and plane-strain states of stress in the transverse (hoop) direction of the cladding. Also, longitudinal tube specimens were also designed to determine the constitutive properties in the axial direction. Finite-element analysis (FEA) and experimental parameters and results were closely coupled to optimize an accurate determination of the stress-strain response and to induce fracture behavior representative of accident conditions. To determine the constitutive properties, a procedure was utilized to transform measured values of load and displacement to a stress-strain response under complex loading states. Additionally, methods have been developed to measure true plastic strains in the gauge section and the initiation of failure using real-time data analysis software. Strain rates and heating conditions have been selected based on their relevance to the mechanical response and temperatures of the cladding during the accidents.
On the Relation Between Engineering Load-Displacement Curves and True Stress Strain Behavior in Tests of Flat Tensile Specimens
Authors: Odette GR , He MY , Donahue EG , Lucas GE
Published: September 2009

The effects of irradiation on true stress-strain constitutive laws associated with large increments of hardening, apparent yield drops, a significant loss of uniform strain and a propensity to microscopic flow localization as derived from the tensile test are evaluated. Analytical and finite element simulations of engineering stress strain curves for flat tensile specimens were performed with systematic variations in the true stressstrain laws. Coupled with large yield stress increases, relatively modest reductions in strain hardening can result in significant reductions in uniform strain. True strain softening eliminates uniform strains, produces apparent yield drops and greatly reduces the post-necking strains. Thus, constitutive laws with varying combinations of yield stress increases and reductions in strain hardening, or modest softening over a limited strain range, rationalize all the major observed engineering stress-strain trends following irradiation. Notably, the true flow stress is persistently increased following irradiation, even at high true strain. Continuum constitutive laws and J2 incremental flow plasticity theory appear to be adequate for modeling the deformation of irradiated materials. While source hardening or micro-localization mechanisms probably play some underlying role, they are neither a necessary nor sufficient condition for producing the behavior observed in tensile tests.
Component-Based Test Specimen Design
Authors: Wimmer SA , DeGiorgi VG
Published: September 2009

Test specimens are traditionally designed to produce a single stress state during the testing process resulting in limited data from individual tests. When material is not readily available, the use of a test specimen that generates a wide range of multiaxial stress states (and therefore more data per test) would be advantageous since this single specimen could replace a series of conventional specimens. Finite element (FE) techniques can be used to determine the stress states of interest in a component and then can be used to custom design a specimen to produce these stress states. The current work examines the use of FE techniques to custom design test specimens that would be more appropriate for typical pressure vessel geometries than traditional tensile test specimens. Stress states for thin and thick wall cylindrical sections are compared with those of standard (ASTM E8) and customized test specimens. An improved match between component and test specimen generated stress states is seen for the custom design specimen.
A Method to Study Deformation Mechanisms in Ion-irradiated Steels Using a Disk Bend Test Technique
Authors: Byun TS , Lee EH , Hunn JD , Farrell K , Mansur LK
Published: September 2009

A disk bend test technique has been developed for transmission electron microscopy (TEM) disks to study deformation mechanisms in ion-irradiated steels. In the bend test, a TEM disk specimen is clamped in a circular holder and indented with a tungsten carbide (WC) ball of 1 mm diameter. Models for evaluating the stress and strain components in the central region of the TEM disks were developed and used to calculate average plastic strain, surface plastic strain, and stress components at top and bottom surfaces of a 316LN stainless steel disk. Deformation regimes and stress state in the disk bend deformation were discussed in relation to the variations of strains and stresses. To investigate deformation mechanisms in irradiated 316LN stainless steel, irradiations of TEM disks were carried out with 0.36 MeV He+ ions and/or 3.5 MeV Fe+ ions at 200°C. Those irradiated samples were deformed up to a surface plastic strain of about 10% in the disk bend jig. To examine the deformation microstructures at the peak damage region, the surface layer to a depth of about 600 nm was removed from the irradiated surface by electrochemical polishing followed by back thinning to perforation. Microstructures were examined in a Philips CM 12 transmission electron microscope at an acceleration voltage of 120 keV. The results displayed changes in deformation mechanism due to ion irradiations.
Specimen Size Effects on Tensile Properties of 2D/3D SiC/SiC Composites
Authors: Nozawa T , Hinoki T , Katoh Y , Kohyama A , Lara-Curzio E
Published: September 2009

Miniaturization of tensile specimen is investigated as one of the important methods to evaluate tensile properties of ceramic matrix composites such as SiC/SiC composites, which are attractive materials for fusion applications. For the establishment of small specimen test techniques, specimen size effects on the tensile properties for P/W, S/W and 3-D SiC/SiC composites were investigated. For 3-D composites, whose failure was characteristic in the sequences of statistical fiber fractures, tensile properties were significantly dependent on specimen size. Decreases of tensile strength due to the weakest link concept, the ratio of damage area, and stress concentration due to the local load sharing theory could be observed. For 2-D SiC/SiC composites, dependencies of tensile properties on specimen size were dissimilar to that for 3-D ones and much smaller, because they failed with another failure mode due to the structural restrictions by weaving fiber bundles, and hence this made it difficult to show fiber strength sufficiently.
A Finite Element Study Relating Load-Penetration Curves and Indentation Topography to Yield and Post-Yield Constitutive Behavior
Authors: He MY , Odette GR , Lucas GE , Schroeter B
Published: September 2009

Finite element simulations of ball and cone indentation tests were performed with systematic variations in the input constitutive laws. The ball indentation simulations were used to evaluate the assumptions and applicability of proposed analytical methods to extract the constitutive laws from instrumented load-penetration data. These methods were found to provide good approximations for a small, but useful, range of strain-hardening rates. However, significant differences were found for low (elastic-perfectly plastic) and high (hardening exponents > 0.2) strain-hardening laws and when significant hardening occurs at small plastic strains (< 0.02). The cone indentation simulations were used to investigate the corresponding effects of constitutive behavior on the pile-up geometry around the indentation. In agreement with previous work, the height-to-width aspect ratio of the pile-up increases with a decreasing strain-hardening exponent. However, the pile-up aspect ratio method is sensitive only to the average strain-hardening exponent, and not to details of the constitutive behavior at very high and low strains.
The Effect of Test Machine Compliance on the Measured Shear Punch Yield Stress as Predicted Using Finite Element Analysis
Authors: Toloczko MB , Abe K , Hamilton ML , Garner FA , Kurtz RJ
Published: September 2009

In previous research involving the use of shear punch test, it was understood that some compliance was present in the test frame and fixturing for a shear punch test, but it was assumed that this compliance would only affect the slope of the loading curve and not the perceived yield point on a shear punch test trace. The present work explores this assumption and its ramifications by simulating the shear punch test with finite element analysis (FEA). The simulations suggest that punch tip displacement is much less than previously assumed, and that for the test frames and fixtures which have been used, crosshead displacement is over an order of magnitude greater than punch tip displacement. This difference in displacements appears to be due to test machine and punch compliance, and a simple elasticity calculation of the compliance of the punch, the test machine, and a specimen gives a result which is in agreement with the FEA simulations. The effect of using punch tip displacement on the observed effective shear yield stress was evaluated using FEA-simulated shear punch tests on several different metals. Yield was measured at several different offset shear strains with a 1.0% offset shear yield strength measurement providing the best correlation with 0.2% offset uniaxial yield strength. When using the 1.0% offset shear yield values, the previously observed material-to-material variability in the tensile-shear correlation all but disappeared. Based on this work, it appears that the material-to-material variations in prior correlations between uniaxial yield strength and shear yield strength are largely due to an interplay between the large test system compliance and material-to-material differences in the work hardening behavior.
The Effect of Specimen Thickness and Grainsize on Mechanical Properties Obtained from the Shear Punch Test
Authors: Toloczko MB , Yokokura Y , Abe K , Hamilton ML , Garner FA , Kurtz RJ
Published: September 2009

For miniature sheet type tensile tests on 316 SS, it is well known that for thin specimens or large grains relative to the specimen thickness, the mechanical properties vary with specimen thickness and the ratio of the specimen thickness to the grainsize. However, the effects of specimen thickness and grainsize on mechanical properties obtained from the shear punch test have not yet been investigated systematically. The current study examines the effect of specimen thickness and grainsize on mechanical properties obtained from the shear punch test. Sheet stock of five different thicknesses ranging from 0.1 mm to 0.3 mm were constructed from 316 stainless steel. Two different heat treatments were used to provide two different grainsizes. Effective shear yield strength and effective shear ultimate strength were measured from shear punch tests at each thickness and grainsize. A measure of strain hardening was also obtained from the data. The results were compared to open literature data from a similar study using miniature tensile specimens. The results show that the shear punch test does not have the same sensitivity as the miniature tensile test for the range of specimen thicknesses and grainsizes examined.
Determination of Mechanical Property Gradients in Heat-Affected Zones of Ferritic Steel Weldments by Shear-Punch Tests
Authors: Karthik V , Laha K , Kasiviswanathan KV , Raj B
Published: September 2009

The heat-affected zone (HAZ) of 2.25 Cr-1 Mo ferritic steel weldments consists of coarse-grained bainite, fine-grained bainite and intercritical structures. In the case of a 2.25 Cr-1 Mo/9 Cr-1 Mo dissimilar weld joint formed with 9 Cr-1 Mo weld metal, the HAZ on the 2.25 Cr-1 Mo base metal side consists of a soft decarburized zone and a carburized zone in the adjacent weld metal. In welded structures of these ferritic steels, a high percentage of failure has been reported to occur in the HAZ of the weldment. The mechanical properties of these individual regions of HAZ are difficult to determine by conventional methods because of the practical difficulties of making mechanical test pieces of adequate dimensions with entirely individual microstructures from the very small regions in HAZ. This paper describes the use of shear punch tests to determine the mechanical properties of the individual regions of HAZ formed in 2.25 Cr-1 Mo (similar) weldments and 2.25 Cr-1 Mo/9 Cr-1 Mo (dissimilar) weld joints. A linear correlation established between the tensile properties and the corresponding properties obtained from the shear punch test of various heat-treated structures has been used to characterize the mechanical properties of individual regions of the HAZ of actual weldments.
RESQUE: Reconstitution Techniques Qualification & Evaluation to Study Ageing Phenomena of Nuclear Pressure Vessel Materials
Authors: van Walle E , Scibetta M , Valo MJ , Viehrig H-W , Richter H , Atkins T , Wootton MR , Keim E , Debarberis L , Horsten M
Published: September 2009

This paper summarizes the experience of the RESQUE project. The final objective of the project was the development of a set of ‘Recommendations for Reconstitution of Non-Irradiated and Irradiated Charpy-size Specimens,’ based on the systematic analysis of the experimental data from the program and on the collective reconstitution experience available in different laboratories within Europe. The paper reviews the general information from RESQUE and summarizes the conclusions. Specific details are given in other contributions to this Symposium.
RESQUE: Determination of the Lowest Acceptable Insert Length for Reconstituted Cv-impact and Precracked Cv Specimen
Authors: Keim E , Langer R , van Walle E , Scibetta M , Valo MJ , Viehrig H-W , Richter H , Atkins T , Wootton MR , Debarberis L , Horsten M
Published: September 2009

One of the tasks within the framework of the EU “RESQUE”- project was to determine the lowest acceptable insert length for reconstituted Charpy V impact (Cv) and pre-cracked Charpy V (PC Cv) specimens. In order to obtain an optimized insert length, Cv impact specimens with three insert lengths ranging from 10 to 20 mm and fracture toughness PC Cv specimens with two different insert lengths of a reference material were manufactured by stud-welding or electron-beam welding and tested under various test conditions. Cv tests on reconstituted specimens exhibited the normal scatter in Charpy energies and that there was no significant influence of the insert length on the transition temperatures. However, the 10 mm insert caused a reduction in the upper shelf energy of 10–15%. The fracture toughness tests carried out in the transition regime showed that the 10 mm insert resulted in a lower estimate (non-conservative) of T0 compared with the values measured on 12mm insert and baseline specimens. It is therefore recommended that at least 12 mm long inserts should be used for fracture toughness testing in the transition region. In the ductile region a trend to lower initiation toughness values at higher temperatures was observed. To avoid this, 20 mm long inserts should be used for J-Δa curves at higher temperatures.
RESQUE: Validation of Specimen Reconstitution with Temperature Measurements and Comparative Testing with Irradiated Materials
Authors: Valo M , Keim E , van Walle E , Scibetta M , Atkins T , Wootton M , Viehrig H , Richter H , Debarberis L , Horsten M
Published: September 2009

This paper continues reporting on the EU-sponsored research project RESQUE [1]. First detailed checks with different ways to instrument reconstitution inserts were performed and thin silver soldered thermocouples were chosen to be used in the project. Temperature transients in welded inserts were measured in detail in order to compare the properties of six different reconstitution systems. The measured temperature transients were repeatable and relatively consistent. Within approximately 4 mm of the near weld seam volume a typical material irradiation temperature was exceeded for a short time. This value was nearly the same by all devices. Validation tests with original and reconstituted specimens were performed. No indication of material annealing in reconstitution, i.e. a trend towards lower transition temperatures, was noticed. As compared to the requirements of ASTM E1253-88, the applied insert lengths were too short. Still original data was repeated with reconstituted specimens, which is an indication that the standard is conservative.
RESQUE: Dependence of Test Results on Reconstituted Specimens with Tolerance Deviations and Variation of End Block Materials
Authors: Viehrig H-W , Richter H , Atkins T , van Walle E , Scibetta M , Valo MJ , Wootton MR , Keim E , Debaberis L , Horsten M
Published: September 2009

This paper continues the presentation of detailed results of the EU-sponsored RESQUE project. Within the RESQUE project it was planned to determine the dependence of Charpy-V test results on tolerance deviations and different end block materials in reconstituted specimens. The conventional Charpy-V parameters - the total impact energy, lateral expansion and shear fracture appearance - are not significantly affected by oversized dimensional variability. Disturbing load oscillations arise from some of the geometrical deviations. This influences the characteristic yield load, yield deflection and impact energy at load maximum. In comparison with the existing scatter there is no significant effect of the end block material on the main Charpy parameters and the characteristic loads.