Design of the upstream decay pipe window of the long baseline neutrino facility

AbstractThe beam windows of high-energy beam lines are important, and it is sometimes difficult to design because it is necessary to ensure particle propagation with minimum disturbance and fulfill mechanical requirements at the same time. The upstream decay pipe window of the long baseline neutrino facility at Fermilab has an extremely large diameter (1.8 m), with a thickness of only 1.5 mm to separate the helium atmosphere in the decay pipe and the nitrogen atmosphere on the other side. Furthermore, the center of this dish-shaped window is expected to be a 200-mm-diameter beryllium dish welded to the outside aluminum alloy A6061, and this welded combination must withstand extreme conditions of a 2.4-MW, high-energy proton beam without leakage. These severe conditions make the design of this window an unprecedented challenge. This paper describes the static thermal-structural analyses based on which the structure has been optimized, as well as dynamic analyses for understanding the shockwave effects originating in the beam. After optimization, the maximum von Mises stresses in the window decreased significantly in both normal operation and accident cases, making our design very reasonable.

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Effective Stresses and Plastic Strain Rates in a Superalloy: a High Temperature In Situ Study by Synchrotron X-Ray TCD

Materials Science Forum ◽

10.4028/www.scientific.net/msf.524-525.775 ◽

2006 ◽

Vol 524-525 ◽

pp. 775-780 ◽

Cited By ~ 1

Author(s):

Alain Jacques ◽

Olivier Ferry ◽

Frédéric Diologent ◽

Pierre Caron ◽

Pierre Bastie

Keyword(s):

High Temperature ◽

Plastic Strain ◽

Tensile Axis ◽

Young Modulus ◽

High Energy ◽

Strain Rates ◽

Data Scatter ◽

Von Mises ◽

Von Mises Stresses

Variations in the lattice parameters of γ and γ' phases perpendicular to the [001] tensile axis were recorded in situ at ~10 minutes intervals using the Triple Axis Diffractometer of the High Energy (ID15) beamline at ESRF. Testing was carried out on an AM1 superalloy specimen with a raft microstructure at high temperature (1072°C) under load steps between 0 MPa and 300 MPa. These data were used to evaluate the Young modulus and the effective (Von Mises) stresses within the γ' rafts and γ corridors, as well the average plastic strain rates of each phase. The recorded stress data scatter was within the MPa range, and should be good enough to probe the elementary mechanisms of plasticity.

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Fatigue Analysis of Large Diameter Threaded Connections Subjected to Dynamic Axial Loads

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.658.177 ◽

2014 ◽

Vol 658 ◽

pp. 177-182 ◽

Cited By ~ 1

Author(s):

Vasile Cojocaru ◽

Calin Octavian Miclosina ◽

Zoltan Iosif Korka

Keyword(s):

Static Analysis ◽

Large Diameter ◽

Fatigue Behaviour ◽

Axial Loads ◽

Element Analysis ◽

Threaded Connections ◽

Local Stresses ◽

Von Mises ◽

Thread Root ◽

Von Mises Stresses

The large diameter threaded connections are components with high importance in the heavy mechanical systems. At the threaded elements subjected to variable loads one of the main causes of failure is represented by fatigue. This phenomenon is accentuated by the occurrence of high local stresses on the thread root. In this context, the correct evaluation of the local stresses and their correlation with the fatigue behaviour has a major importance in the correct assessment of remaining life of large diameter threaded connections.The paper is focused on the finite element analysis of the large diameter threaded bolts with two types of threads profiles: trapezoidal and square. For the two types of threads the simulations were performed using four nominal diameter and two different loading setups. The bolts were summited to static analysis in order to determine the local stresses distribution in the threaded area. The maximum values of Von Mises stresses obtained in the static analysis were exported to fatigue studies. The differences between the results obtained for the two types of threads are outlined.

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Characterization of thermal barrier coatings formed by electon-beam physical vapor deposition (EB-PVD)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010015410x ◽

1989 ◽

Vol 47 ◽

pp. 426-427

Author(s):

Ozer Unal

Keyword(s):

Thermal Barrier Coatings ◽

Physical Vapor Deposition ◽

Ceramic Coating ◽

High Vacuum ◽

Ceramic Coatings ◽

High Energy ◽

Thermal Barrier ◽

Protective Oxide ◽

Barrier Coatings ◽

Energy Beam

Interest in ceramics as thermal barrier coatings for hot components of turbine engines has increased rapidly over the last decade. The primary reason for this is the significant reduction in heat load and increased chemical inertness against corrosive species with the ceramic coating materials. Among other candidates, partially-stabilized zirconia is the focus of attention mainly because ot its low thermal conductivity and high thermal expansion coefficient.The coatings were made by Garrett Turbine Engine Company. Ni-base super-alloy was used as the substrate and later a bond-coating with high Al activity was formed over it. The ceramic coatings, with a thickness of about 50 μm, were formed by EB-PVD in a high-vacuum chamber by heating the target material (ZrO2-20 w/0 Y2O3) above its evaporation temperaturef >3500 °C) with a high-energy beam and condensing the resulting vapor onto a rotating heated substrate. A heat treatment in an oxidizing environment was performed later on to form a protective oxide layer to improve the adhesion between the ceramic coating and substrate. Bulk samples were studied by utilizing a Scintag diffractometer and a JEOL JXA-840 SEM; examinations of cross-sectional thin-films of the interface region were performed in a Philips CM 30 TEM operating at 300 kV and for chemical analysis a KEVEX X-ray spectrometer (EDS) was used.

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The promises and perfidy of cryomicroscopy and analysis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010016964x ◽

1994 ◽

Vol 52 ◽

pp. 382-383

Author(s):

Patrick Echlin

Keyword(s):

Low Temperature ◽

High Energy ◽

Short Paper ◽

List Type ◽

Time Resolved ◽

Energy Beam ◽

Cellular Analysis ◽

Dissolved Ions ◽

Embedding Medium ◽

Low Temperature Microscopy

The unusual title of this short paper and its accompanying tutorial is deliberate, because the intent is to investigate the effectiveness of low temperature microscopy and analysis as one of the more significant elements of the less interventionist procedures we can use to prepare, examine and analyse hydrated and organic materials in high energy beam instruments. The promises offered by all these procedures are well rehearsed and the litany of petitions and responses may be enunciated in the following mantra.Vitrified water can form the perfect embedding medium for bio-organic samples.Frozen samples provide an important, but not exclusive, milieu for the in situ sub-cellular analysis of the dissolved ions and electrolytes whose activities are central to living processes.The rapid conversion of liquids to solids provides a means of arresting dynamic processes and permits resolution of the time resolved interactions between water and suspended and dissolved materials.The low temperature environment necessary for cryomicroscopy and analysis, diminish, but alas do not prevent, the deleterious side effects of ionizing radiation.Sample contamination is virtually eliminated.

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Rendering Fat and Heavy Fischer-Tropsch Waxes Mixtures (0–100%) Fast Pyrolysis Tests for the Production of Ethylene and Propylene

Processes ◽

10.3390/pr9020367 ◽

2021 ◽

Vol 9 (2) ◽

pp. 367

Author(s):

Martyna Murat ◽

Zahra Gholami ◽

Josef Šimek ◽

Daily Rodríguez-Padrón ◽

José Miguel Hidalgo-Herrador

Keyword(s):

Linear Chain ◽

High Energy ◽

Chain Structure ◽

Nitrogen Atmosphere ◽

Energy Materials ◽

Fischer Tropsch ◽

Pyrolysis Products ◽

Product Composition ◽

Rendered Fat ◽

Linear Chain Structure

A great emphasis is placed on searching for efficient sources to produce renewable fuels due to the actual trends in avoiding the use of fossil resources to mitigate the environment’s deterioration. Thus, the use of waste from the food or wood industry for the production of biofuels is widely researched and may contribute to sustainable general development. Rendered fat and Fischer-Tropsch waxes are high-energy materials which could be used for the pyrolysis reaction. Therefore, in this study, the effect of reaction parameters and feedstock composition on the distribution of the pyrolysis products has been examined. The experiments were carried out in a nitrogen atmosphere in a multi-shot pyrolizer instrument equipped with GC-FID. First, the influence of the temperature was examined at 785, 800, and 815 °C. The highest yield to olefins was observed at 815 °C. The effect of triglycerides and paraffins contents (0–100% with 10% ramp) in the feedstock on the product composition was investigated at 815 °C. The gas chromatography analyses revealed that the feedstock composition did not significantly affect the product composition due to the high temperature and the long linear chain structure similarities between the free fatty acids and Fischer-Tropsch waxes.

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Impact of mandibular prognathism on morphology and loadings in temporomandibular joints

Biomedical Engineering / Biomedizinische Technik ◽

10.1515/bmt-2019-0298 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Jingheng Shu ◽

Quanyi Wang ◽

Desmond Y.R. Chong ◽

Zhan Liu

Keyword(s):

Finite Element Analysis ◽

Pearson Correlation ◽

Morphological Parameters ◽

Element Analysis ◽

Mandibular Prognathism ◽

Temporomandibular Joints ◽

Pearson Correlation Analysis ◽

Von Mises ◽

Von Mises Stresses ◽

Asymptomatic Subjects

AbstractLoadings in temporomandibular joints (TMJs) are essential factors in dysfunction of TMJs, and are barely noticed in treatment of maxillofacial deformity. The only approach, which can access stresses in TMJs, could expend day’s even weeks to complete. The objective of the study was to compare the differences of the morphological and biomechanical characteristics of TMJs between asymptomatic subjects and patients with mandibular prognathism, and to preliminarily analyze the connection between the two kinds of characteristics. Morphological measurements and finite element analysis (FEA) corresponding to the central occlusion were carried out on the models of 13 mandibular prognathism patients and 10 asymptomatic subjects. The results indicated that the joint spaces of the patients were significantly lower than those of the asymptomatic subjects, while the stresses of patients were significantly greater than those of asymptomatic subjects, especially the stresses on discs. The results of Pearson correlation analysis showed that weak or no correlations were found between the von Mises stresses and the joint spaces of asymptomatic subjects, while moderate, even high correlations were found in the patients. Thus, it was shown to be a feasible way to use morphological parameters to predict the internal loads of TMJs.

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Fabrication of circular cooling channels by cold metal transfer based wire and arc additive manufacturing

Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture ◽

10.1177/0954405421995613 ◽

2021 ◽

pp. 095440542199561

Author(s):

Shaohua Han ◽

Zhongzhong Zhang ◽

Pengxiang Ruan ◽

Shiwen Cheng ◽

Dingqi Xue

Keyword(s):

Additive Manufacturing ◽

High Energy ◽

Cooling Effect ◽

High Deposition Rate ◽

Cooling Channel ◽

Conformal Cooling Channel ◽

Conformal Cooling ◽

Energy Beam ◽

Cooling Channels ◽

Straight Line

Additive manufacturing has been proven to be a promising technology for fabricating high-performance dies, molds, and conformal cooling channels. As one of the manufacturing methods, wire and arc additive manufacturing displays unique advantages of low cost and high deposition rate that are better than other high energy beam-based ones. This paper presents a preliminary study of fabricating integrated cooling channels by CMT-based wire and arc additive manufacturing process. The deposition strategies for fabricating circular cross-sectional cooling channels both in conformal and straight-line patterns have been investigated. It included optimizing the welding torch angle, fabricating the enclosed semicircle structure and predicting the collision between the torch and constructed part. The cooling effect test was also conducted on both the conformal cooling channel and straight-line cooling channel. The results affirmed a higher cooling efficiency and better uniform cooling effect of the conformal cooling channel than straight-line cooling channel.

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Interior-stress fields produced by a general axisymmetric punch

Friction ◽

10.1007/s40544-020-0478-9 ◽

2021 ◽

Author(s):

Longxiang Yang ◽

Zhanjiang Wang ◽

Weiji Liu ◽

Guocheng Zhang ◽

Bei Peng

Keyword(s):

Hankel Transform ◽

Elastic Half Space ◽

Stress Fields ◽

Dual Integral Equations ◽

Total Load ◽

Interior Stress ◽

Von Mises ◽

Von Mises Stresses ◽

Relationship Of ◽

Analytical Expressions

AbstractThis work is a supplement to the work of Sneddon on axisymmetric Boussinesq problem in 1965 in which the distributions of interior-stress fields are derived here for a punch with general profile. A novel set of mathematical procedures is introduced to process the basic elastic solutions (obtained by the method of Hankel transform, which was pioneered by Sneddon) and the solution of the dual integral equations. These processes then enable us to not only derive the general relationship of indentation depth D and total load P that acts on the punch but also explicitly obtain the general analytical expressions of the stress fields beneath the surface of an isotropic elastic half-space. The usually known cases of punch profiles are reconsidered according to the general formulas derived in this study, and the deduced results are verified by comparing them with the classical results. Finally, these general formulas are also applied to evaluate the von Mises stresses for several new punch profiles.

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