To create such a mesh, an additional partition is made, corresponding to a circle centred around the crack tip. The spider web will be inside this circle. A hex-dominated swept meshing technique is assigned within the newly partitioned cell. If the sweep path is along the edge of the circle, wedge elements will be created at the centre of the circle.
If this is used along with a singularity with collapsed element sides, collapsed elements will be used instead of wedge elements. For more complex geometries where the sweep path is not along the edge of the circle, it can be beneficial to partition an inner and an outer circle and define a single layer of wedge elements in the inner circle. A locally refined mesh is created by specifying the amount of elements along the circular edge and along the crack.
It is recommended to use at least 16 elements around a complete circle. Each ring of elements along the crack corresponds to a contour integral. The first 2 contour integrals are commonly neglected, because the crack tip is so close it can lead to unwanted effects. Contour integrals close to for example boundaries can be influenced by other things than the crack.
Therefore, contour integrals , close to the crack, are commonly used for evaluation. Quadratic elements are used to aid in capturing stress concentrations. When the instance is meshed and the part is colour coded based on the element types, it is clear that while the elements at the crack tip are wedge shaped, the hexahedral C3D20R element type is used. Querying elements on both sides of the crack, shows that the elements do not share nodes. When the crack is defined and a mesh is created, output can be requested.
The number of contours number of layers around crack front for which the integral is calculated and the type of integral needs to be specified. It is not possible to request more than one type of integral in a single history output, but it is possible to request them in separate history outputs. Of course just specifying a crack does not allow us to run a simulation.
Material properties, loads and boundary conditions need to be applied as well. In this case, a linear elastic steel is used and the gear is fully constrained in the centre, while a force is applied to separate both teeth and open the crack. Using a deformation scale factor of , and opened crack is visible. Many history outputs were created.
For each contour at each node of the crack line, there is a history output. Node sets are automatically created to show which history outputs corresponds to which node.
For one of the nodes, the given values for the J-integral are as shown in the image. Be aware that the scale does not start at 0. The bigger markers are for the first two contours. If a reasonable value is to be find, all contours should be the same. Material and element enhancements — The multiscale material modeling capability has been enhanced tosupport: — Heat transfer, coupledtemperature-displacement, and linear perturbation procedures.
Contact enhancements — Available in FP. Other key enhancements — Results can now be imported from multiple previoussimulations — Partial activation of elements can be specified during asimulation — The Abaqus Scripting Interface supports multiscale materialmodeling commands — Unsymmetric matrix input is now supported — Eulerian-type inlet and outlet conditions can be specified in SPHsimulations.
You must then select the components for which the documentation should be installed Figure 4. In this case all documentation components are installed for the sake of completion, though this is not necessary if you already know that you will neve use a specific component.
Figure 4: Select the components for which the documentation components to install. The documentation will now be installed. If the license server is to be installed, we are asked for the installation directory. Usually the default is fine. We then need to choose whether to only install the license server, or also start it. The default is to start it.
Check the box for files only — do not start the license server program if the license server should not be started. The location of the license file is then requested Figure 5. If Abaqus is already used, it is typically the newest. If this is the first Abaqus installation, this is a file that is received by e-mail. The installation of the established products Abaqus, Tosca and fe-safe is next.
The components to be installed are then selected Figure 6. Note that now Abaqus, fe-safe and Tosca can be selected from the same window, while previously each was installed individually and required a separate installation folder to be provided. The space required is given. Typically, all Abaqus related components are to be installed. If Tosca is to be used with Abaqus or another structural solver , install Tosca Structure.
If you want to use fe-safe, typically you will want to install most fe-safe related components, except the tutorial models for programs that you do not use and the interface to Abaqus for ODB versions that you do not use.
You are then asked for the License server Figure 7. If the license server is on a different machine, fill in the name or IP address of this machine. To include a port number, use portnumber machine. The system will now try to locate the license server.
If this fails, an error message will be given. While it is possible to circumvent this and continue the analysis anyway, we do not recommend this. If the license server cannot be found, this is often due to a firewall blocking the connection. This is easier to troubleshoot during the installation than afterwards. Therefore, we recommend not continuing the installation, but solving the connectivity issue first. If the connectivity to the license server is ok, the next step is to select the default Working directory Figure 8.
This is the default location of abaqus job files and of the abaqus. It also serves as scratch directory for Tosca Fluid.
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