K.N. Song¹

Structural Durability & Health Monitoring, Vol.8, No.3, pp. 209-222, 2012, DOI:10.32604/sdhm.2012.008.209

Abstract A PHE (Process Heat Exchanger) is a key component in transferring the high temperature heat generated from a VHTR (Very High Temperature Reactor) to the chemical reaction for the massive production of hydrogen. A performance test on a small-scale PHE prototype made of Hastelloy-X is currently under way a small-scale gas loop at the Korea Atomic Energy Research Institute. Previous research on the elastic high-temperature structural analysis of the small-scale PHE prototype has been performed using the parent material properties over the whole region. In this study, an elastic-plastic high-temperature structural analysis considering the mechanical properties in the weld-affected zone… More >

K.N. Song¹

Structural Durability & Health Monitoring, Vol.7, No.4, pp. 297-306, 2011, DOI:10.3970/sdhm.2011.007.297

Abstract The IHX (Intermediate Heat Exchanger) of a VHTR (Very High Temperature Reactor) transfers 950° heat generated from the VHTR to a hydrogen production plant. The Korea Atomic Energy Research Institute (KAERI) has manufactured a small-scale prototype of a PCHE (Printed Circuit Heat Exchanger) under consideration as a candidate of the IHX. In this study, as a part of high-temperature structural integrity evaluation of the small-scale PCHE prototype, we carried out a macroscopic structural behavior analysis including structural analysis modeling and thermal/elastic structural analysis under small-scale gas loop test conditions as a precedent study to a performance test. The results obtained… More >

A.B. Mahmud Hasan^1,2, M A Wahab¹, S.M. Guo¹

Structural Durability & Health Monitoring, Vol.4, No.4, pp. 231-240, 2008, DOI:10.3970/sdhm.2008.004.231

Abstract This paper presents details analysis of Heat Affected Zone (HAZ) in High Temperature Vacuum Tube Furnace (HTVTF) to predict fracture region in tube wall due to thermal stress from temperature variation across its thickness. A simple mathematical model is used to illustrate stress concentration arising due to thermal stresses in tube wall and HAZs. Finite element model and analysis were carried out utilizing finite element analysis commercial codes. Combination of thermal stress due to temperature difference determine fracture region. Experimental and simulation results of inside temperature of tube are observed and similar relation have been found. Observation of heat affected… More >

Yun Zhang¹, Lingfeng Zhang², Zhiwei Shan³, Lu Wang^1,*, Weiqing Liu¹

Journal of Renewable Materials, Vol.7, No.11, pp. 1093-1108, 2019, DOI:10.32604/jrm.2019.07335

Abstract It is well known that the use of woods as construction materials can embody carbon content of structural members, which can enhance the urban sustainability. However, due to the combustibility of wood, its current application is restricted. To broaden the application of wood, its thermal responses exposed to fire (high temperature) is investigated in this study. Firstly, the wood kinetic parameters are determined by coats-redfern method using thermal gravimetric (TGA) data. Secondly, the density and thermal conductivity are obtained from parallel and series models. Thirdly, the specific heat capacity formula is presented considering latent and decomposition heat, which can be… More >

Liangchi Zhang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.3, pp. 93-94, 2011, DOI:10.3970/icces.2011.017.093

Abstract Understanding the deformation mechanisms of metals under the coupled attack of high strain, high strain rate and high temperature (coupled H3 effect) has become more and more important to the development of new manufacturing technologies. High speed machining (HSM), a new technology to cut high hardness materials, is a typical example, as HSM has become an essential process in making ultra-precision, high-integrity components for devices and structures in the automotive, aeronautical, aerospace and biomedical industries. Nevertheless, due to the high machining speed in HSM, many problems which do not appear in conventional machining will take place. New plasticity theories are… More >

Xue Feng^*, Xiang Wang, Guobing Zhang, Huimin Xie, Helong Yu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.4, pp. 115-116, 2011, DOI:10.3970/icces.2011.020.115

Abstract Most ceramic materials, because of their inherent brittleness, are susceptible to catastrophic failure under conditions of thermal shock. A novel method for measuring the dynamical deformation is proposed by using of high speed digital image correlation in high temperature environment. The nature texture of ceramic materials can be used as speckle while filters and monochrome produced by LED are applied to suppress black-body radiation and enhance the luminous intensity.

The light from the heated material can alter the Grayscale of material surface and the recognition for material surface will become more and more difficult with the temperature increase. In… More >

M. Tsuda¹, T. Asada¹, N. Ohno^1,2, T. Igari³

The International Conference on Computational & Experimental Engineering and Sciences, Vol.10, No.3, pp. 2-2, 2009, DOI:10.3970/icces.2009.010.097

Abstract In this study, homogenized elastic-viscoplastic behavior of plate-fin structures fabricated for compact heat exchangers is investigated. First, the homogenized behavior is numerically analyzed using a fully implicit mathematical homogenization scheme of periodic elastic-inelastic solids. A power-law creep equation is assumed to represent the viscoplasticity of base metals at high temperatures. The plate-fin structures are thus shown to exhibit significant anisotropy as well as compressibility in both the elastic and viscoplastic ranges of the homogenized behavior. Second, a non-linear rate-dependent macroscopic constitutive model is developed by utilizing the quadratic yield function proposed for anisotropic compressible plasticity. The resulting constitutive model is… More >

F. De Rosa¹, A. Esposito¹

FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.1, pp. 107-128, 2012, DOI:10.3970/fdmp.2011.008.107

Abstract An investigation was conducted to evaluate the feasibility and the performance of an electrically heated composite leading edge for aircraft anti-icing applications. A prototype was designed, manufactured and equipped with a High Temperature composite leading edge with embedded Ni alloy resistance fed by a DC power supply unit. Running wet and fully evaporative functional modes have been verified both analytically and experimentally with reasonable agreement. A room temperature thermal endurance test has been run for 10⁴ cycles aiming to preliminary verify the integrity of the composite laminate after the imposed thermal stress. The EHCLE system (Electrical Heated Composite Leading Edge)… More >

Sanjeev Saxena¹, Raghvendra Singh², Geeta Agnihotri²

CMC-Computers, Materials & Continua, Vol.36, No.3, pp. 257-270, 2013, DOI:10.3970/cmc.2013.036.257

Abstract The present numerical study is an attempt to understand the dependency of characteristic distance on the fracture specimen thickness and temperature. The presented work will be useful to establish the characteristic distance prediction methodology using three dimensional FEM model. Based on the methods proposed for the numerical prediction of characteristic distance, it comes out that it depends on fracture specimen thickness and finally it converges after a specified thickness of fracture specimen. In Armco iron material, characteristic distance varies in temperature ranges where dynamic strain ageing phenomenon is observed, initially decrease and then increases again. More >