Modeling High Temperature Materials Behavior for Structural Analysis


Book Description

This monograph presents approaches to characterize inelastic behavior of materials and structures at high temperature. Starting from experimental observations, it discusses basic features of inelastic phenomena including creep, plasticity, relaxation, low cycle and thermal fatigue. The authors formulate constitutive equations to describe the inelastic response for the given states of stress and microstructure. They introduce evolution equations to capture hardening, recovery, softening, ageing and damage processes. Principles of continuum mechanics and thermodynamics are presented to provide a framework for the modeling materials behavior with the aim of structural analysis of high-temperature engineering components.




High Temperature Structures and Materials


Book Description

High Temperature Structures and Materials is a compilation of the proceedings of the Third Symposium on Naval Structural Mechanics held at Columbia University in New York on January 23-25, 1963. The symposium provided a forum for discussing structural mechanics under conditions of elevated temperatures. Emphasis is placed on the various aspects of structural design for elevated temperature service. The following areas are covered: material aspects of elevated temperature design; effects of high-speed environment; thermal stress analysis; and design criteria and reliability. This book is comprised of 13 chapters and begins by assessing the temperature dependence of elastic and anelastic properties in solids, followed by a discussion on the thermo-mechanical behavior of ceramics. Subsequent chapters explore the physical aspects of creep; thermal fatigue and its relation to creep rupture and mechanical fatigue; materials aspects of the re-entry problem; and problems of heat conduction and melting. Thermal stresses in viscoelastic solids are also considered, along with creep design and aspects of reliability under conditions of elevated temperature creep and fatigue. This monograph will be a valuable resource for material physicists and mechanical and structural designers concerned with the problem of elevated temperature effects on the performance and safety of modern structures.




Thermal Stresses and Temperature Control of Mass Concrete


Book Description

Methods of controlling mass concrete temperatures range from relatively simple to complex and from inexpensive too costly. Depending on a particular situation, it may be advantageous to use one or more methods over others. Based on the author's 50 years of personal experience in designing mass concrete structures, Thermal Stresses and Temperature Control of Mass Concrete provides a clear and rigorous guide to selecting the right techniques to meet project-specific and financial needs. New techniques such as long time superficial thermal insulation, comprehensive temperature control, and MgO self-expansive concrete are introduced. - Methods for calculating the temperature field and thermal stresses in dams, docks, tunnels, and concrete blocks and beams on elastic foundations - Thermal stress computations that take into account the influences of all factors and simulate the process of construction - Analytical methods for determining thermal and mechanical properties of concrete - Formulas for determining water temperature in reservoirs and temperature loading of arched dams - New numerical monitoring methods for mass and semi-mature aged concrete




Coatings for High-Temperature Structural Materials


Book Description

This book assesses the state of the art of coatings materials and processes for gas-turbine blades and vanes, determines potential applications of coatings in high-temperature environments, identifies needs for improved coatings in terms of performance enhancements, design considerations, and fabrication processes, assesses durability of advanced coating systems in expected service environments, and discusses the required inspection, repair, and maintenance methods. The promising areas for research and development of materials and processes for improved coating systems and the approaches to increased coating standardization are identified, with an emphasis on materials and processes with the potential for improved performance, quality, reproducibility, or manufacturing cost reduction.




High-temperature Structural Materials


Book Description

Conventional materials, such as nickel based alloys, will not be able to match the required performance specifications for the future generation of high temperature materials. This book reviews the characteristics and potential of a wide range of candidate superalloy replacements, such as ceramics, intermetallics, and their composites. Particular attention is devoted to the problems of processing and design with these materials.







An Instrument for Measuring the Thermal Conductance of High-temperature Structural Materials


Book Description

A thermal conductivity apparatus employing the absolute guarded hot plate principle was designed developed and fabricated for the United States Air Force. The primary objective of this instrument is to test honeycomb structures at elevated temperatures. A secondary objective is to test super-alloys, ceramics, and cermets. In general these operational requirements were met with calibration runs on copper to 1800 F and Al2O3 to 3000 F falling within the prescribed accuracy limits. Further thermal conductivity tests have been completed on Rene' 41 Honeycomb, Titanium Alloy Honeycomb, L605 Cobalt Alloy Honeycomb, Stainless Stainless Steel, Rene' 41, and Fused Silica. Thermal conductance tests on Tungsten and Columbium are planned. A detailed discussion is made of instrumentation and materials compatability problems encountered during the testing program.




Thermomechanics of Composite Structures under High Temperatures


Book Description

This pioneering book presents new models for the thermomechanical behavior of composite materials and structures taking into account internal physico-chemical transformations such as thermodecomposition, sublimation and melting at high temperatures (up to 3000 K). It is of great importance for the design of new thermostable materials and for the investigation of reliability and fire safety of composite structures. It also supports the investigation of interaction of composites with laser irradiation and the design of heat-shield systems. Structural methods are presented for calculating the effective mechanical and thermal properties of matrices, fibres and unidirectional, reinforced by dispersed particles and textile composites, in terms of properties of their constituent phases. Useful calculation methods are developed for characteristics such as the rate of thermomechanical erosion of composites under high-speed flow and the heat deformation of composites with account of chemical shrinkage. The author expansively compares modeling results with experimental data, and readers will find unique experimental results on mechanical and thermal properties of composites under temperatures up to 3000 K. Chapters show how the behavior of composite shells under high temperatures is simulated by the finite-element method and so cylindrical and axisymmetric composite shells and composite plates are investigated under local high-temperature heating. The book will be of interest to researchers and to engineers designing composite structures, and invaluable to materials scientists developing advanced performance thermostable materials.




Designing Steel Structures for Fire Safety


Book Description

Structural design in fire conditions is conceptually similar to structural design in normal temperature conditions, but often more difficult because of internal forces induced by thermal expansion, strength reduction due to elevated temperatures, much larger deflections, and numerous other factors. Before making any design decisions it is esse