st-4: structural analysis model - main concepts -

TechnischeUniversitätDresden

ST-4: Structural Analysis Model- Main Concepts -

P. Katranuschkov, M. WeiseTU Dresden

[email protected]@cib.bau.tu-dresden.de

Presentation at the IAI Structural Project Coordination Meeting #3Loughborough, UK, June 2002

26.06.200220020626_ST-Meeting_maw-pik.ppt

TechnischeUniversitätDresden Outline

1. Project status

2. Scope of the structural analysis domain

3. Modelling issues

4. Walkthrough


TechnischeUniversitätDresden Project status

available at: http://cib.bau.tu-dresden.de/icss/structural_papers.html

Volume III “Structural Analysis Domain” is now internally finalized and is currently reviewed by international groups.Revised version issued this week.

ST-4 consists basically of four parts: Vol. 0 - Application scenarios

Vol. I - Resource extension

Vol. II - Steel construction domain

Vol. 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


TechnischeUniversitätDresden Scope - Overview

Structural Engineering Model

IFC – Project ModelArch. 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

Current focusis on the directarch.-struct.

data exchange

Current focusis on the directarch.-struct.

data exchange


TechnischeUniversitätDresden 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


TechnischeUniversitätDresden Out of Scope

Dynamic analysis

Prestressing

Finite element topology

Results w.r.t.

- Stresses- Strains

- …


TechnischeUniversitätDresden Exchange scenarios

Exchange scenarios were discussed and are formalized in Volume 0 “Application Scenarios”.

CheckingEngineer

StructuralEngineer

Architect*

FacilityManager*

HVACDesigner*

ProjectManager*

Fabrication(Steel)

Detailing(Steel)

Detailing(Timber,

Concrete)**Fabrication

(Timber,Concrete)**

IFC2x

ST-4Model

Extension

ConstructionManager

CostCalculation


TechnischeUniversitätDresden Exchange 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

Exchange scenarios were discussed and are formalized in Volume 0 “Application Scenarios”.


TechnischeUniversitätDresden Project extension schemas

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

Resources: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




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.)




IFCREPRESENTATIONEXTENSIONRESOURCE (used by the Structural Analysis Domain)

- Extension needed to define topology items using the global coordinate system Optional, 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 edges Optional, but useful for analysis tools




IFCPRODUCTEXTENSIONEXTENSION (used by both parts)

- Definition of relationships (association of

profile properties and

IfcConstructionElement )

Core layer:Core layer:

IFCSHAREDBLDGELEMENTSEXTENSION(minimal extension, used by Steel Construction Domain)

Interoperability layer:Interoperability layer:



Domain layer:Domain layer:

IFCSTEELCONSTRUCTIONDOMAIN(used by Steel Construction Domain)

IFCSTRUCTURALANALYSISDOMAIN(used by Structural Analysis Domain)

several entities needed for analysis

worth having a GUID


TechnischeUniversitätDresden Modelling Issues

Using new classes for the definition of structural elements with an optional reference to the represented building element

Building ElementsBuilding Elements

Structural Representation

Structural RepresentationGeometrical

RepresentationGeometrical

Representation

1:n 1:n

Other Representation

Other Representation

1:n

* IfcRelAssignsToStructuralMembers - Fig. 4-8 page 22 @see pg. 6 in Vol. III

The connection is defined by an

optional Rel.-object*



Using the existing topology resource for the definition of the topology and geometry

Topological Item

Topological Item

MemberMember

ConnectionConnection

ActivityActivity

- 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



Connectivities are explicitly defined by relationship objects

- 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

Three connectivity types exist:



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

Profile property definition

Load definition


TechnischeUniversitätDresden Walkthrough

Basic structural elements

Item Activity

Connection Member

IfcProduct

AssignmentSelect

IfcRelConnectsStructuralMember

IfcRelConnectsStructuralActivity

IfcRelConnects

1

1

1

1

Action Reaction

IfcBuildingElement



Grouping of elements

IfcSystem

IfcKernel.IfcGroup

ResultGroup

LoadGroup

IfcLoadGroupTypeEnum

AnalysisModel

IfcAnalysisTheoryTypeEnum

BOOLEAN

1

ResultForLoadGroup

TheoryType

IsLinear

HasResults S[1:?]

(INV) ResultGroupFor S[0:1]

Loaded By S[1:?]

(INV) LoadedGroupFor S[0:?]



Usage of resources

Material properties => as in IFC

Profile properties => see pg. 37

IfcBoundaryCondition

Connection

IfcRelConnectsStructuralMember

Activity

IfcStructuralLoad

IfcStructuralConnectionConditions

AppliedCondition

AppliedCondition

st-4: structural analysis model - main concepts -

Documents

structural system

load cases

load types

load flow

temperature load boundary

application scenarios

building model

german project icss26