Run SfePy to solve the updated problem and view the solution (assuming Stress_strain() function as a post_process_hook(). The problem options were also updated to call the The stiffness tensor – thus it was necessary to update the materialsĪccordingly. The stress function ( de_cauchy_stress()) requires as input The updated file imports all of the previous definitions in R """ Diametrically point loaded 2-D disk. The programming of the problem description file is well documented in The next step in the process is coding the SfePy problem definition file. Nodes and elements can alsoīe identified by defining regions, which is addressed later.Īnother open source python option to view. Which elements are connected to which nodes. Yet? Luckily, SfePy provides some useful mesh functions to indicate Need to subtract the number of lines in the Gmsh file + 1. So to get the corresponding element number in SfePy you’ll The surface labels as numbered in Gmsh follow on from the line Under the Visibility tab enable the node and surface labels. NodeĪnd element numbers can also be viewed in Gmsh – under the mesh option Numbering is 0, and elements 76 and 77 are connected to this node. Thus the node at the center of the model in SfePy The numbering in medit starts atġ as shown. Mesh file with medit you can see the node and element numbering by Numbering in SfePy start at 0 and not 1 as is the case in Gmsh and It is important to note that node and element The mesh file provides the coordinates of the nodes and theĮlement connectivity. You’ll notice that the mesh contains 55 vertices (nodes) and 83 triangleĮlements. Mesh file that will be used in the tutorial. Meshes in Gmsh’s native format as well (Shift-Ctrl-S). Note that when you do this the file cannotīe reopened by Gmsh so it is always a good idea to also save your Reformatted the mesh file to a 2D formatĪnd delete the Edges block. Gmsh saves the mesh in a 3D format and includes some extra geometry If you open the sh file using a text editor you’ll notice that Hint: Check the drop down in the Save As dialog for the different The figures that follow show the various stages in the model process. With the geometry of the model defined, add a mesh by clicking on the Still under Geometry add a ruled surface. Next add a Circle arc connecting two of the points to form the Next add two straight lines connecting the points. Points (geometry elementary entities) at the following coordinates: The ITS specimen has a diameter of 150 mm. The meshing program Gmsh is used here to very quickly mesh the Will be meshed and boundary conditions will be established to indicate this To take advantage of this symmetry only one quarter of the 2D model Symmetrical about the x- and y-axes passing through the centre of theĬircle. Furthermore, the geometry of the model is Solve this problem using SfePy the first step is meshing a suitableĪssuming plane strain conditions, the indirect tensile test may be modelled These solutions may be approximated using finite element methods. Specimen, the compressive stress is 3 times the tensile stress and theĪnalytical formulation for these are, respectively: Result of the point loads P are a function of the diameter and The tensile and compressive stresses that develop in the specimen as a Model this problem using finite elements the indirect tensile test canīe simplified to represent a diametrically point loaded disk as shown in Loading exceeds its tensile strength then the specimen will fail. When the tensile stress that develops in the specimen under The test is usually run by loading the specimen at a constantĭeformation rate of 50 mm/minute (say) and measuring the load This test a cylindrical specimen is loaded across its diameter toįailure. Materials is the indirect tensile strength (ITS) test pictured below. Problem statement ¶Ī popular test to measure the tensile strength of concrete or asphalt SfePy is followed: a model is meshed, a problem definition file isĭrafted, SfePy is run to solve the problem and finally the results of The typical process to solve a problem using This primer presents a step-by-step walk-through of the process to solveĪ simple mechanics problem. A beginner’s tutorial highlighting the basics of SfePy.
0 Comments
Leave a Reply. |