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ST71.30 Thermal 


ST71.30.10 Thermal / Heat Transfer  
0.8 MB 
ST71.30.10.1 Nonlinear Weld Thermal Analysis Welding presents a great challenge for everyone involved, from the designer to the analyst to the manufacturer. This is because welds encompass a wide variety of nonlinear behaviours including melting, differential hardening, radiative heat transfer and large amounts of shrinkage after cooling. In this case we consider a short segment of steel web being welded to a flange. It is welded on both sides simultaneously in an attempt to avoid differential shrinkage deformation in the web. The general... 

2.2 MB 
ST71.30.10.2 Transient Analysis of a Frying Pan A bimetallic copper and cast iron frying pan with an oak handle is analysed using Strand7s thermal solvers. The goal is to determine the effective cooking temperature of the cooking surface as well as the fire safety and durability of the wooden handle. Additionally, the mechanical response of the frying pan to the transient thermal solution is explored using a simplified axisymmetric model. The geometry is symmetric. Create a new model (File/New) with SI units, but change the temperature... 

5.9 MB 
ST71.30.10.3 Estimating Heat Loss from a Building This Webnote presents two examples of analysis of heat loss from building elements. Doubleglazed windows and corner details are included to demonstrate realistic complexity of a building and introduce equivalent conductivity of air gaps. The two examples included are a 2D example of a wall and window, and a 3D example including a corner detail. Steady state and transient heat analyses are performed. An example of a wall and a window is presented. Open the file ST71.30.10.3 2D example initial.st7. ... 

0.8 MB 
ST71.30.10.4 Approximating an Air Gap in Thermal Analysis A common situation in thermal analysis is when two adjacent surfaces are separated by an air gap. Examples include internal walls subjected to fire, and the gaps between double and triple glazed windows. In such cases, convective cells form between the two surfaces, and radiative heat exchange may also be significant if higher temperatures are involved. Without the use of CFD, we can approximate the effective thermal conductivity of the gap and fill it with elements which match this conductivity. 

ST71.30.20 Thermal / Mechanical  
0.8 MB 
ST71.30.20.1 Nonlinear Weld Mechanical Analysis A quasi static nonlinear mechanical weld analysis is performed using thermal results and nonlinear Factor vs Temperature tables to calculate the mechanical response of a welded beam flange. This topic refers to the thermal results found in Webnote ST71.30.10.1 Nonlinear Weld Thermal Analysis. In this case we consider a short segment of steel web being welded to a flange. It is welded on both sides simultaneously in an attempt to avoid differential shrinkage deformation in the web. ... 

0.7 MB 
ST71.30.20.2 Thermal Expansion of a Kiln Ring The thermal expansion of a 250mm thick refractory lining operating at 600 C is investigated. Contact with a steel outer shell is discussed. Because the geometry is regular, we can use the Snap Grid tool to generate the plates in one go. Create a new model with Nmm units. Create a Cylindrical UCS using Global/Coordinate Systems. Choose the System to be Cylindrical and the Type to be XY. Place the origin of the Cylindrical UCS at the origin of the Global Cartesian System. ... 

1.0 MB 
ST71.30.20.3 Nonlinear Thermal Expansion Strand7 allows for the continuous variation of coefficient of thermal expansion with respect to changing temperature. The variability of the coefficient can be expressed in various ways, including thermal strain vs temperature, as the average coefficient over a range of temperatures, or as an instantaneous coefficient which must be integrated to get the total thermal strain. This Webnote outlines how to use Strand7 to model nonlinear variations of thermal expansion coefficient with respect to temperature. 

1.3 MB 
ST71.30.20.5 Modelling Temperature Gradients Temperature gradients are important because they cause local differential thermal expansion. This difference in thermal expansion between adjacent parts of connected material can cause high stresses and can be a critical load case. Temperature gradients, in which two parts of a structure are not at the same temperature, i.e. where one part is hot and another part is relatively cool, produce local bending and stress. 

0.5 MB 
ST71.30.20.6 Thermal Expansion Analysis Thermal expansion analysis aims to include the effects of heating and cooling of a structure from its asbuilt state. Three basic engineering problems arise from this phenomenon: differential heating across a structure, uniform heating of restrained structure, and uniform heating of a multimaterial structure. 

0.8 MB 
ST71.30.20.7 ThermalMechanical PressFit Operations This Webnote presents the steps used to model a sequence of events representing a shrinkfit situation between two pipes. Thermal loading of the outer pipe is used to expand it so that it slides over the inner pipe. The outer pipe is then cooled to produce contact between the pipes. Next, the pipes are welded together to form a shaft. Operational load, represented by shaft rotation, is then applied to the shaft and finally, thinning of the shaft due to wear is simulated. 

26.7 MB 
ST71.30.20.15 Analysis of Steel Vessel Subjected to Hot Dip Galvanising Process This Webnote investigates the feasibility of using the Hot Dip Galvanising method to apply a protective zinc coating to a steel vessel. The process involves lowering the preheated vessel into a molten zinc bath, and withdrawing the vessel from the bath after a short period of immersion. The Strand7 API is used to facilitate the application of timedependent loads that simulate the dipping process. The analysis aims to determine the thermally induced stress and resulting risk of developing cracks during the process. 

ST71.30.30 Thermal / Other Uses  
0.5 MB 
ST71.30.30.1 Caisson Soil Seepage Analysis Soil seepage is governed by the same equations as heat transfer (the diffusion equation). It is thereby possible to use the Strand7 heat solver to solve seepage problems, including pore pressure and flow rates. In the following example, this method is applied to an axisymmetric mesh representing a hole being bored in a mud flat. The ground water level is assumed to be flush with the mud surface. The axisymmetric mesh is annotated below. For visualisation purposes, the equivalent 3D structure... 
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