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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The submodel is run as a separate analysis from the global analysis. As described above, nodal output requests to the results file or hkw database file must be used in the global analysis to save the values of the driven variables at the submodel boundary. Comparison of the Mises stress in the continuum mesh plate for the submodel with scaled boundary condition top and the shell-to-solid coupling analysis with scaled load bottom.
Prescribing boundary conditions at nodes. The dashed line on the shell model is replaced by the shaded surfaces of the solid wbaqus submodel.
Defining the driven variables in the submodel. Therefore, the tolerance value plays a significant role in such cases.
Take advantage of this live online course right from your desk. The acoustic nodal pressures from the global analysis must be written to the results file for the acoustic mesh in contact with the structural surface of interest. To preclude certain elements from driving the submodel, you can specify a global element set abqus limit the search to this subset of the solis model.
A geometric tolerance is used to define how far a boundary node in the submodel can lie outside the exterior surface of the global model, as that surface is interpolated in the global, undeformed finite element model.
Unlike shell-to-solid submodeling, which first performs a global analysis on a shell model followed by a submodel analysis with a continuum model, the shell-to-solid coupling model uses a single analysis, with solid and shell elements used in different regions. The results for the submodel dynamic cases agree well with the global results. The continuum meshes accurately model the fillet radius at the joint. Hence, it is possible to calculate the stress concentration in the fillet.
The continuity of displacements and the minimal distortion of the stress field at the shell-to-solid interface indicate that the shell-to-solid coupling has been modeled accurately. The global model in a submodeling analysis must define the submodel boundary response with sufficient accuracy. If a very fine solid mesh 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.
Thus, the response at the boundary of the local region is defined by the solution for the global model. Therefore, if the default amplitudes are used, the concentrated force will be reduced linearly to zero over the period of the step in a static analysis and immediately in a dynamic analysis.
If this parameter is not used in a frequency extraction step, the nodes will be assigned to the primary base. Central Time CT — It is your responsibility to ensure that any particular use of the submodeling technique provides physically meaningful results.
The maximum Mises stresses at the integration points and nodes for the reference solution, submodel, and shell-to-solid coupling analyses are shown in Table 1. All nodes of the submodel where variables will be driven in any step see Figure If the distance between the driven nodes and the free surface of the global model falls within the specified tolerance, the solution variables from the global model are extrapolated to the submodel.
New nodes cannot be added to the total set of driven nodes defined for the submodel; this set of driven nodes is a fixed part of the model definition.
Shell-to-solid submodeling and shell-to-solid coupling of a pipe joint
This field can be left blank if only one degree of freedom is being sumbodeling. The continuum meshes extend 10 mm along the pipe length, have a radius of 25 mm in the plane of the plate, and use four layers through the thickness.
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. Solid submodel overlaid on the shell model in the deformed state, using a magnification factor of The exterior tolerance in shell-to-shell submodeling.
Online-Submodeling with Abaqus
The continuum meshes used in the static submodeling and shell-to-solid coupling analyses are identical. Node definitions for the S4R global model.
The following types of submodeling are provided global-to-submodel: Specifying the driven nodes in acoustic-to-structure submodeling. Instead of interpolating between the results at the start of the step and the results of the first increment on the results file, ABAQUS will simply use the results of the first increment as long as the submodel step time is less than the step time of the first increment on the results file.
An edge-based surface is defined at the free edge submodeoing the pipe. Neither the coupled thermal-electrical procedure nor any of the mode-based dynamics procedures can be used on the submodel level. The boundary where the submodel is driven is a set of surfaces in the submodel but is a set of lines in the shell reference surface in the global model, as shown in Figure The example could also be expanded by including plastic material behavior in the submodel while using an elastic global model solution.
If the submodel analysis step time is different from the global analysis step time, use the TIMESCALE parameter to adjust the time variable for the driven nodes’ amplitude functions. Limitations in shell-to-solid submodeling.
Use the following option to define the geometric tolerance as an absolute distance: Next, run a submodel heat transfer analysis using the mesh mesh2 that is required for the final submodel thermal-stress analysis, and write the nodal temperatures to the results or output database file. Set this parameter equal to the name that will be used to reference the boundary condition in user subroutine VDISP.
Mixing general and linear abaqua steps in shell-to-solid submodeling. The boundary nodes cannot lie in regions of the global model where there are only axisymmetric solid elements with nonlinear, asymmetric deformation CAXA elements. Run a heat transfer shel of the global model, and write the nodal temperatures to the results or output database file. Global analysis step basis Submodel step basis Global increment specified in definition of submodel boundary condition Driven variable basis General General none Linear perturbation General none General Static, linear perturbation i Linear perturbation Static, linear perturbation i.
Thus, only one layer of driven nodes lies within the center zone, and hoq these nodes have all three displacement components driven by the global solution.
Comparison of the Mises stress in the plate for the reference solution top and the shell-to-solid coupling analysis bottom.