See “Shell-to-solid submodeling and shell-to-solid coupling of a pipe joint,” Section For example, a static analysis performed in ABAQUS/Standard can drive a. Perform solid-to-solid, shell-to-shell, and shell-to-solid submodeling. Targeted This course is recommended for engineers with experience using Abaqus. script to perform the steps of the method in an automatic manner. Using the Keywords: Abaqus, Ansa, Meta, Submodelling, Multiscale analysis, Polymers .. scales from shells to solids, further constraints must be introduced, increasing the .
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First degree of freedom constrained. Node number of a real node that is originally located coincident with the phantom node.
The driven nodes for the submodel are the nodes lying on the specified surface. Node definitions for the C3D20R submodel that uses the S4 global model. Saving the results to the results file. ABAQUS will then have the complete solution history including the solution state at the beginning of a step from which a submodel may be driven. Loading The pipe is subjected to a concentrated load acting in the x -direction applied at the free end, representing a shear load on the pipe.
Online-Submodeling with Abaqus
Data lines for acoustic-to-structure submodeling Data lines for acoustic-to-structure submodeling: This may be necessary if the model has closely spaced entities that, when meshed, contain coincident nodes. In this case, the transfer of results from the global analysis to the submodel can be achieved only by accessing the output database.
Magnified solid submodel of the pipe-plate joint. As illustrated in Table 1 and Figure 9the Mises stress computed in the shell-to-solid coupling analysis agrees very well with the reference solution. Saving results from a global model with a physical time scale.
To avoid this problem, write the nodal output to the output database or the results file using the same frequency for all nodes involved in the interpolation and choose a frequency that will allow the history in the submodel to be reproduced accurately. In addition, submodeling cannot be used in conjunction with symmetric model generation or symmetric results transfer.
If a very fine solid perfoorm is used in the thickness direction and substantial transverse shear stresses are transferred, it may be necessary to make the center zone size large enough that multiple layers of nodes lie inside the zone. Submodeling with general and linear perturbation steps. For acoustic-to-structure submodeling, the loads due to acoustic pressure acting at the driven nodes of the submodel are activated by specifying pressure degree of freedom 8 along with the driven node set.
Element definitions for the reference model with C3D20R elements. Adaptive meshes should not be used in the global model.
Shell-to-solid submodeling and shell-to-solid coupling of a pipe joint
Specifying the driven nodes in acoustic-to-structure submodeling. Submodeling is the technique used in Abaqus for analyzing a local part of a model with a refined mesh, based on interpolation of the solution from an initial global model usually with a coarser mesh onto the nodes on the appropriate parts of the boundary of the submodel.
For the remaining driven nodes only the displacement components parallel to the global model midsurface are driven from the global model. The load is scaled in the second on. The acoustic pressure from the global model is interpolated to the submodel driven nodes. For complicated geometries it can be advantageous to assign a different center zone size to different nodes or node sets. A node sshell be driven from the global model in some steps and have user-prescribed boundary conditions in other steps.
The time scale cannot be specified in frequency domain analyses or in linear perturbation steps.
You can specify different shell thicknesses if, for example, a local thickness change is being investigated; however, ABAQUS does not check the validity of these differences. Data lines for shell-to-solid abaqis Data lines for shell-to-solid submodeling: It is not recommended to have all the variables at all the nodes in the submodel driven by the global solution. Run a data check analysis on the submodel.
However, if the transverse shear stresses at the submodel boundary are high and the submodel is highly refined in the thickness direction, high local stresses may develop since the shear force at the submodel boundary is transferred only at the driven nodes within the center zone. The submodel can refer only to a global model results file that is from a binary compatible platform. Global shell model of pipe-plate structure.
The driven nodes and any loads applied to the local region determine the solution in the submodel. For solid-to-solid and shell-to-shell submodeling specify the individual degrees of freedom to be driven. Neither the coupled thermal-electrical procedure nor any of the mode-based dynamics procedures can be used on the submodel level. The continuum meshes used in the static submodeling and shell-to-solid coupling analyses are identical.
Thus, the response at the boundary of the local region is defined by the solution for the global model.
Automatically selecting the driven variables in shell-to-solid submodeling. Mesh constraints must be used normal to an Eulerian boundary region to allow material to flow through the region. Similarly, the results will always be correctly interpolated when using the output database to transfer the results from the global model to the submodel, because the zero increment is always written to the output database.
Hence, it is possible to calculate the stress concentration in the fillet. Set this parameter equal to the name that will be used to reference the boundary condition in user subroutine VDISP. This surface is coupled to a reference node that is defined at the center of the pipe using a distributing coupling constraint.