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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Online-Submodeling with Abaqus
Element definitions for the S4 global model. Shell-to-solid coupling is a feature in Abaqus by which three-dimensional shell meshes can be coupled automatically to three-dimensional solid meshes. For shell-to-solid submodeling the driven degrees of freedom at the driven nodes are chosen automatically, depending on the distance between the driven node and the global model shell reference surface.
Specifying the driven nodes in shell-to-solid submodeling. If the global element set is defined at the assembly level, you may provide the element set name without qualifying it with the assembly name in a submodel analysis.
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. If the driven boundary lies at the border between a solid and a shell region, the driven nodes must be moved a small distance away from the solid region see Figure There are two exceptions.
Geometry and model In this problem the joint between a pipe and a plate is analyzed. Kinematic boundary conditions The plate is clamped along all edges. For the dynamic cases the load is applied gradually over the entire step time by using a smooth-step amplitude curve.
Finally, run the submodel submodeilng analysis using sehll temperatures as field variables obtained from the results or output database file for the submodel heat transfer analysis and submoveling displacements as driven variables obtained from the global thermal-stress analysis. For solid-to-solid and shell-to-shell submodeling specify the individual degrees of freedom to be driven.
Any loads that are applied in the submodel region must soljd imposed in the submodel analysis in the usual way. In a problem involving an acoustic fluid submodel driven by a structural global model, for example, acoustic interface elements should be created on the submodel’s driven boundary with the structure. Education Partner Training Click here for a listing of partner-led training classes.
It is not recommended to have all the variables at all the nodes in the submodel driven by the global solution. Submodeling allows you to study a local region of a model based on an existing solution from a global model. This course is a customized subset of the Substructures and Submodeling with Abaqus.
Since the submodel is a separate analysis, submodeling can be used to any number of levels; a submodel can be used as the global model for a subsequent submodel. Comparison of the Mises stress in the plate for the reference solution top and the shell-to-solid coupling analysis bottom.
The boundary nodes cannot lie in regions of the global model where there are only one-dimensional elements beams, trusses, links, axisymmetric shells since ABAQUS does not provide the necessary interpolation of results for such elements.
Shell-to-solid submodeling models a region with solid elements, when the global model is made up of shell elements. 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.
This parameter is relevant only when some of the variables being prescribed have nonzero magnitudes. 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. Global step number and Global increment. Types of submodeling available. For the remaining driven nodes only the displacement components parallel to the global model midsurface are driven from the global model.
Mesh constraints are typically applied on the edge of a sliding boundary region to fix it spatially.
Only element-based surfaces are allowed in acoustic-to-structure submodeoing. The difference in the maximum Mises stress between the submodel analysis and the shell-to-solid coupling solution see Figure 10 can be partially attributed to the fact that the global shell model is more flexible than the shell-to-solid coupling model.
Only translational and rotational degrees of freedom are supported for user-prescribed boundary conditions.
Shell-to-solid submodeling and shell-to-solid coupling of a pipe joint
Set perorm parameter equal to the value by which the driven variables read from the global analysis are to be scaled. No such refinement was performed in this example. For example, an element set named top in part instance I-1 of assembly Assembly-1 must be referred to by Assembly This check is only approximate if the global model has varying shell thickness or if the shell reference surface is offset from the midsurface.
C3D20R submodel that uses the Anaqus global model.
The distance checked against the specified exterior tolerance is shown in Figure If a very fine solid mesh is performm 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. The following types of submodeling are provided global-to-submodel: A reference static solution consisting entirely of C3D20R continuum elements is also included see Figure 4.
It can also be useful when creating a submodel near a contact pair that may include the response from nodes on the incorrect side of the contact pair which will occur unless the entire submodel lies within the discretized geometry ssolid the body that is intended to be overlaid by the submodel. The material response defined for the submodel may be different from that defined for the global model.
By default, nodes in the submodel must lie within a distance calculated by multiplying the average element size in the global model by 0. These values affect only field-variable-dependent material properties, if any. Scale time period of global step to time period of submodel step. Alternatively, you can use global element sets to associate the submodel driven nodes with the appropriate global model elements.
Hence, this area is modeled with continuum elements to gain a better understanding of the deformation and stress state. Specifying the driven nodes in the submodel. Use the following option to define the geometric tolerance as an tto distance: 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.
To simplify calculations, the closest point in the global model is calculated as the intersection of a line drawn through the node on the submodel with submodeoing reference surface of the shell in the global model.
Perfom node can be driven from the global model in some steps and have user-prescribed boundary conditions in other steps. Comparison of out-of-plane displacement in perfform plate for the reference solution top and the shell-to-solid coupling analysis bottom.