ST-4: Structural Analysis Model - Main Concepts -

Presentation at the IAI Structural Project Coordination Meeting #3Loughborough, UK, June 2002 ST-4: Structural Analysis Model- Main Concepts - P. Katranuschkov, M. Weise TU Dresden Peter.Katranuschkov@cib.bau.tu-dresden.de Matthias.Weise@cib.bau.tu-dresden.de

Outline • Project status • Scope of the structural analysis domain • Modelling issues • Walkthrough

Project status • ST-4 consists basically of four parts: FVol. 0 - Application scenarios FVol. I - Resource extension FVol. II - Steel construction domain FVol. III - Structural analysis domain • ST-4 is developed by the IAI GS Chapter.Development work is supported by the EU project ISTforCE and the German project iCSS • Volume III “Structural Analysis Domain” is now internally finalized and is currently reviewed by international groups.Revised version issued this week. available at: http://cib.bau.tu-dresden.de/icss/structural_papers.html

Scope - Overview IFC – Project Model Arch. Model Current focusis on the directarch.-struct. data exchange Structural Engineering Model • No extension of building elements (e.g. foundations => ST-2) • Conceptually considered, no extensions proposed(structural system, load types, load flow, …) • Extension for the structural analysis domain with optional relationships to the architectural model

Scope • Planar and/or spatial structural analysis models with - line and surface elements - supports - connectivity and support conditions • Specification of loadings including - concentrated, line, surface and temperature loads - assignment to load groups, load cases and load combinations • Specification of different structural analysis modelsfor one and the same building model=> use of the IFC nesting concepts • Analysis results for forces and displacements

Out of Scope • Dynamic analysis • Prestressing • Finite element topology • Results w.r.t. • Stresses • Strains • …

Exchange scenarios Architect* FacilityManager* HVACDesigner* ProjectManager* Fabrication(Steel) Detailing(Steel) ConstructionManager CostCalculation CheckingEngineer StructuralEngineer ST-4Model Extension Detailing(Timber,Concrete)** IFC2x Fabrication(Timber,Concrete)** • Exchange scenarios were discussed and are formalized in Volume 0 “Application Scenarios”.

Exchange scenarios • Exchange scenarios were discussed and are formalized in Volume 0 “Application Scenarios”. • Architect  Structural Engineer • Structural Engineer  Structural Engineer • Structural Engineer  Detailing (Raw Design) • Structural Engineer  Construction Manager • Detailing (Raw design)  Structural Engineer • Detailing (Raw design)  Detailing (Raw design) • Detailing (Steel)  Detailing (Steel) • Detailing (Steel)  NC-Fabrication • Detailing (Steel)  Construction Manager • NC-Fabrication  Construction Manager • Detailing (Steel)  Tendering, Awarding, Invoicing

Project extension schemas • Resources: • IFCACTIVITYRESOURCE/ IFCSTRUCTURALLOADRESOURCE(used by the Structural Analysis Domain) • -Load definitions (single, linear, planar loads and displacements, temperature load) • -Boundary and connection (slippage, failure) conditions for point and linear cases • IFCGEOMETRICMODELEXTENSIONRESOURCE (used by the Steel Construction Domain) • -New Entity IfcSurfaceCurveSweptAreaSolid

Project extension schemas • Resources: • IFCMATERIALPROPERTYRESOURCE (used by both parts) • Added attributes and entities for the definition of materialproperties - mainly needed for analysis and dimensioning (Young’s modulus, shear modulus, …, yield stress, ultimate stress, …) • IFCMEASUREEXTENSIONRESOURCE (used by both parts) • Extension of the measure resource proposed  common agreement is needed here as to how the measure types shall be named and used; currently there is a semantic inconsistence b/n the meaning and the measure name albeit units are correct

Project extension schemas • Resources: • IFCPROFILEEXTENSIONRESOURCE(used by the Steel Construction Domain) • Entities for the geometric definition of profiles (see IfcProfileDef) • IFCPROFILEPROPERTYRESOURCE(used by both parts) • Completely new resource for the definition of profile properties, mainly needed for analysis (This definition can be applied to building elements as well as to structural members. Additionally there exists an optional link b/n the profile properties and the profile definition.)

Project extension schemas • Resources: • IFCREPRESENTATIONEXTENSIONRESOURCE(used by the Structural Analysis Domain) • -Extension needed to define topology items using the global coordinate systemOptional, but especially convenient for structural analysis applications • IFCTOPOLOGYEXTENSIONRESOURCE(used by the Structural Analysis Domain) • -Rationale: needs for the definition of faces, for example to reuse edgesOptional, but useful for analysis tools

Project extension schemas • Core layer: • IFCPRODUCTEXTENSIONEXTENSION(used by both parts) • -Definition of relationships (association of profile properties and IfcConstructionElement) • Interoperability layer: • IFCSHAREDBLDGELEMENTSEXTENSION (minimal extension, used by Steel Construction Domain)

Project extension schemas • Domain layer: • IFCSTEELCONSTRUCTIONDOMAIN(used by Steel Construction Domain) • IFCSTRUCTURALANALYSISDOMAIN(used by Structural Analysis Domain) • severalentities needed for analysis worth having a GUID

Modelling Issues • Using new classes for the definition of structural elements with an optional reference to the represented building element Building Elements Other Representation 1:n The connection is defined by anoptional Rel.-object* 1:n 1:n Structural Representation Geometrical Representation * IfcRelAssignsToStructuralMembers - Fig. 4-8 page 22@see pg. 6 in Vol. III

Modelling Issues Member Topological Item Activity Connection • Using the existing topology resource for the definition of the topology and geometry • Connectivity is identified by having the same topological item • Geometry is defined by using the IFC capabilities => IfcStructuralCurveMember represents any curve. A topological item is normally used by several structural elements @see pg. 12 in Vol. III

Modelling Issues • Connectivities are explicitly defined by relationship objects Three connectivity types exist: • Between structural members and building elements => IfcRelAssignsToStructuralMembers • Between structural members and structural connections (defining connection properties)=> IfcRelConnectsStructuralMember and subtypes • Between activities (loads) and either structural items or building elements=> IfcRelConnectsStructuralActivity

Modelling Issues • The structural analysis domain uses the axes convention of the structural engineering domain • important for the definition of profile properties and for the definition of loads Load definition Profile property definition

Walkthrough IfcProduct 1 Item Activity 1 1 Connection Member Action Reaction IfcBuildingElement IfcRelConnectsStructural Member AssignmentSelect 1 IfcRelConnectsStructural IfcRelConnects Activity • Basic structural elements

Walkthrough IfcSystem IfcAnalysisTheory Analysis HasResults S[1:?] TypeEnum Model (INV) ResultGroupFor S[0:1] TheoryType Loaded By S[1:?] (INV) LoadedGroupFor S[0:?] BOOLEAN IfcLoadGroupType IsLinear Enum LoadGroup ResultForLoadGroup ResultGroup 1 IfcKernel.IfcGroup • Grouping of elements

Walkthrough IfcBoundaryCondition IfcStructuralLoad AppliedCondition AppliedCondition Connection Activity IfcRelConnectsStructural Member IfcStructuralConnectionConditions • Usage of resources Material properties => as in IFC Profile properties => see pg. 37

ST-4: Structural Analysis Model - Main Concepts -