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ST71.55 Verification 


ST71.55.10 Verification / Analytical  
1.2 MB 
ST71.55.10.1 Analytical Clutch Torque Capability Verification An automotive plate clutch is designed to slip at 400 Nm of transmitted torque. Each of the two sides of the clutch plate contributes to the transfer of torque from the engine to the transmission. The clutch plate is shown schematically at right. The plates are pressed between the flywheel and clutch spring with an axial force . The results of a Strand7 displacement controlled nonlinear static analysis are compared to the analytical solution for the critical slip torque. Given the clutch... 

2.3 MB 
ST71.55.10.2 Comparison of Element Types for Thin Structure Whenever a finite element analysis is to be undertaken, one of the first considerations to be made by the analyst relates to element choice. This document summarises the different elements that can be used to model thin walled structure and compares the accuracy of the results for a specific problem. The model considered in this example is a rectangular flat plate. The text, Formulas for Stress and Strain by Roark and Young (Table 26 8a) contains a theoretical solution for the centre displacement... 

0.7 MB 
ST71.55.10.3 Large Displacement of a Flat Plate Strand7 offers a geometric nonlinear solver, capable of analysing structures that undergo large displacements. In this benchmark, a square plate, clamped at all four edges, is loaded by a uniform normal pressure. The nonlinear displacement and stress response is compared with a published analytical solution. The reference solution is given in National Advisory Committee for Aeronautics (NACA) Technical Note No. 847, Square Plate with Clamped Edges Under Normal Pressure Producing Large Deflections... 

0.5 MB 
ST71.55.10.4 Block Friction Sliding to a Stop The distance to rest depends on the energy balance of the system. By energy methods the analytical result for distance slid to rest is: Also of interest is the angle at which infinite sliding will occur: These equations do not consider tipping. In this case, so . To make the problem more interesting, an angle near this critical angle is chosen (25). The analytical distance to rest is then calculated to be: The Strand7 model is shown at right. Note that from Equation 1, the mass... 

0.7 MB 
ST71.55.10.6 Finding the Buoyant Balance of Two Bonded Cubes The settling angle of a pair of floating bonded cubes is a function of the specific gravity of each cube. This Webnote compares the Strand7 buoyancy solution with the analytical settling angle. The analytical solution, for a rigid body, can be derived by using geometric relationships after assuming that both the far left and far right walls of the bonded assembly are partially submerged. where: = Gravitational acceleration = Density of the fluid (kg/m3) = Specific... 

0.6 MB 
ST71.55.10.7 RC Module Verification This Webnote looks at some simple reinforced concrete examples using the Plate RC Module and compares the results to design code calculations, hand calculations and published data such as an NM Strength Interaction Diagram. 

2.8 MB 
ST71.55.10.8 Hertzian Contact This topic investigates the modelling of two round objects held together by force, forming a point or line contact interface, and compares the analysis results with that of Hertzian contact formulas. We will first look at two special cases contact between two solid spheres and contact between two solid cylinders. Then we will examine the behaviour of a more complex contact scenario between a wheel and a rail. Two solid spheres of diameters 100 mm and 150 mm are pressed together with a force... 

2.3 MB 
ST71.55.10.14 Linear Buckling Analysis of Flat Panels This Webnote presents a simple method to analyse and verify the buckling of flat panels using different examples from the theory of elastic stability. Various combinations of inplane compression, bending and shear loads are investigated. 

ST71.55.20 Verification / Experimental  
1.3 MB 
ST71.55.20.1 Curved Composite Bridge Validation The Curved Steel Bridge Research Project (CSBRP) was set up by the Federal Highway Administration to investigate the fundamental behaviour of curved steel bridge structural systems and their component members. This Webnote presents an overview of how Strand7 can be used to: Model the bridge components; Model the assembly of the components following a typical construction sequence (encompassing locked in stresses and deflections); and Incrementally load the bridge to ultimate failure. ... 

1.3 MB 
ST71.55.20.2 Numerical vs Experimental Elastoplastic Postbuckling of a Column In this Webnote, the postbuckling behaviour of aluminium flats is demonstrated and compared with experimental results by Ziolkowski and Imielowski [1]. ... 

6.4 MB 
ST71.55.20.5 Catamaran Compartment  Comparison with Nastran A structural FEA model of an aluminium catamaran compartment is constructed in Strand7 using a range of tools such as the lofting and extrusion tools (see ST71.50.20.22 Modelling a Ship Hull by Lofting). The CQUAD4 element appears to be the most commonly used Nastran 4node shell element; this is a 5degreeoffreedom (DOF) per node element. This is also the default element exported by Strand7 when exporting a Strand7 file to the Nastran format. Unlike the Nastran CQUAD4, the Strand7 4node... 

ST71.55.30 Verification / Codes and Standards  
0.7 MB 
ST71.55.30.1 Heat Transfer Benchmark BS EN ISO 10211 2007 (E) Case 1 Problem Definition A two dimensional analysis of heat transfer through half a square column, with known surface temperatures, is validated on Strand7 against the analytical results to ISO 10211:2007 (E) Test Case 1. Details of the geometry are provided within the standard and illustrated below. The analytical solution at 28 points of an equidistant grid is given. This standard states that the difference between the temperatures at the prescribed locations of the cross section calculated... 

0.9 MB 
ST71.55.30.2 Heat Transfer Benchmark BS EN ISO 10211 2007 (E) Case 2 Problem Definition A two dimensional heat transfer analysis of the model shown in the figure below is carried out. Details of the geometry, material data and the applied convection conditions are provided within the standard: BS EN ISO 10211: 2007 (Case 3). The model simulates the heat flow through a building component with materials having varying thermal conductivities. This standard states that: The difference between the temperatures calculated by the method being validated and... 

1.4 MB 
ST71.55.30.3 Heat Transfer Benchmark BS EN ISO 10211 2007 (E) Case 3 Problem Definition A three dimensional heat transfer analysis of the model shown in the figures below is carried out. Details of the geometry, material data and the applied convection conditions are provided within the standard: BS EN ISO 10211: 2007(E) Case 3. The model simulates the heat flow from the corner of a building  walls and floor are modelled. This standard states that: The difference between the temperatures calculated by the method being validated and the temperatures... 

2.1 MB 
ST71.55.30.4 Heat Transfer Benchmark BS EN ISO 10211 2007 (E) Case 4 Problem Definition A three dimensional heat transfer analysis of the model shown in the figures below is carried out. Details of the geometry, material data and the applied convection conditions are provided within the standard: BS EN ISO 10211: 2007 (Test Case 4). The model simulates a thermal bridge consisting of an iron bar penetrating an insulation layer. 1. Top 2. Top View 3. Adiabatic cutoff planes 4. External surface 5. Internal surface 6. Iron bar 7.... 

3.4 MB 
ST71.55.30.5 Evolution of Beam Temperature using ISO834 Fire Curve In this Webnote, the evolution of steel temperature over time is analysed based on the ISO834 fire curve, i.e. the Gas Temperature vs Time relationship as per Eurocode 3 Part 12. An IPE500 steel section is used for such analysis over a period of an hour and its results compared against analytical results from Eurocode 3. The temperature dependent material properties are considered. 

ST71.55.40 Verification / Quality Assurance  
0.6 MB 
ST71.55.40.1 Model Checking and Quality Assurance This Webnote serves as a guide to QA for Strand7 FEA models and results. It provides a template with which the analyst can benchmark the quality of a given model and results for the intended purpose. The general flow starts with basic modelling checks, then checks dependencies for different types of analysis, and finally covers verification of results and conclusions. 

0.5 MB 
ST71.55.40.10 Strand7 FAQ This Webnote presents some of the most commonly asked questions in relation to FE modelling issues when using Strand7, along with brief guidance on how to address these issues. Links are provided to Webnotes with further details where appropriate. 
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