MSC.Patran Laminate Modeler Solid Element Support December 21, 2004

S6-2 Motivation Laminates are getting thicker Use in primary structures Must recover out-of-plane stresses Need laminated solid elements Laminate solid elements available MSC.Marc MSC.Dytran MSC.Nastran SOL 600 ABAQUS, ANSYS Difficult to model composite structure Must enhance solid laminate modeling

S6-3 Prior Support Layup defined on shell elements Appropriate properties applied to solid elements Created by extrusion Single element through thickness Separate Orphan Mesh Apply equivalent solid material (MAT9) to solid elements in laminate

S r2 Enhancements Enhanced Extrusion Single Element Manual Split Element Per Ply Enhanced Orphan Mesh Support Apply laminated materials Better documentation

S6-5 Extrusion Methods Single Element Basic Capability Manual Split Uses split plies Material split* Thick = 0 Per Ply Detailed analysis

S6-6 Manual Split Allows very flexible specification of solid elements Split plies would typically lie at the interface of different materials Split plies cannot end in the middle of laminate Easiest to cover all selected area

S6-7 Extrusion Options Snap faces to surfaces Enforce ply continuity Fill voids with resin Divide elements

S6-8 Scales through thickness to match selected surface/s Models closed-mould processes e.g. Resin Transfer Snap faces to surfaces

S6-9 Snap Faces Average normals on selected nodes (on selected elements) calculated Snap points calculated at intersection of normal with snap surfaces Duplicates deleted (e.g. where node on edge/vertex of surface/s) Only 2 closest snap points to selected node used Laminate thickness calculated using appropriate ply thicknesses and continuity option Offsets calculated using LM offset definition and laminate thickness Snap points ignored if beyond snap tolerance from face points Default snap tolerance relative to laminate thickness (100%) Absolute snap tolerance can also be input Face points snapped to matching snap points Relevant face point (of 2) is one closest to snap point If both snap points are closest to one face point, snap point closest to the face point is chosen Intermediate dimensions (ply locations) scaled pro-rata

S6-10 Snap Faces Selected Node Face Point (on face of laminate) Snap Point 2 (on snap surface) Selected Element Snap Points must be within Snap Tolerance of the laminate face, otherwise ignored Laminate midplane Laminate top face Laminate bottom face Average Normal On Selected Node Snap Point 1 (on snap surface)

S6-11 Snap Faces Results created for: Original Thickness Snap Scale Final Thickness

S6-12 Enforce ply continuity Standard laminate analysis ignores ply continuity completely OK for shells, may be significant in a detailed analysis Also affects laminate thickness Valid for all extrusion methods Manual Split method enforces continuity of split plies

S6-13 Fill voids with resin Voids will exist at ply drop-offs For Per Ply option, void area will be defined by a PENTA/TETRA element This MUST be filled with an isotropic material mimicking resin This material will be given the (arbitrary) orientation defined by the global x-axis

S6-14 Divide Elements Elements may be divided through the thickness Allows greater resolution Laminate divided automatically A layer may appear in more than one divided laminate