1 GSA Steel Member Design Steel Design (Steel member capacity check)

2 GSA Steel Member Design 1.Design codes covered 2.Analysis layer & design layer 3.Member-element relationship 4.Creation of members 5.Member properties 6.Member & element local axis 7.Member forces & moments 8.Design checks carried out 9.Results 10.Limitations Steel Design

3 GSA Steel Member Design 1. Design codes covered  BS5950 – 2000  AISC - LRFD3  Eurocode 3  Indian code – IS800

4 GSA Steel Member Design 1.Analysis layer 1.Elements 2.Rigid constraints 3.… 2.Design layer 1.Members 2.Geometric entities - line, area and region etc 3.… 2. Analysis layer & design layer

5 GSA Steel Member Design 3. Member–element relationship  One member can contain one or more elements which are in a straight line and coincide with the member  Example of a member and the associated elements Element (8,1) Element (1,5) Member (8, 7) Node 8 Element (5,7) Node 1Node 5Node 7 Span 1Span 2Span 3 Member Node 1Member Node 2Member Node 3Member Node 4

6 GSA Steel Member Design 4. Creation of members  Generate from existing elements (from tool menu)  Type in on member table in the same way typing elements in element table  Use Sculpt tools, e.g. copy & paste etc, the same as working on elements

7 GSA Steel Member Design 5. Member properties  Section property uDefine the section geometry. Normally, it should be the same as the property of the associated elements at the end of design.  Design property uDefine material grade, effective area & effective length etc.

8 GSA Steel Member Design 5. Member properties  Restraint property uDefine point and/or continuous restraints along the member that will be used to calculate the effective length of the member by GSA uIf effective length is known & defined explicitly in Design property table, the restraint property is not required

9 GSA Steel Member Design 6. Member local axis used in design X (strong bending axis) YZ Member Y X (node 1 to node 2) Z Element

10 GSA Steel Member Design 7. Member forces and moments  Forces and moments in the member uThey are taken from the corresponding elements for the chosen analysis or combination case uThe forces and moments from elements are considered as factorised forces and moments and no load factors will be applied in the design stage

11 GSA Steel Member Design 7. Member forces and moments  The sub-spans of a member uAs an user – an element in a member is considered as a sub-span, e.g. if there are three elements in a member, there are three sub-spans uWithin the program – a sub-span has linear moment distribution and the maximum difference of the linear moment diagram and the true moment diagram is smaller than a small tolerance, so there will be many sub- spans if the moment diagram of the member is not linear

12 GSA Steel Member Design  Local axial  Local moment (major axis)  Local moment (minor axis)  Local shear (major axis)  Local shear (minor axis)  Local torsional (Not so accurate) 8. Design checks being carried out

13 GSA Steel Member Design  Buckling (about major axis)  Buckling (about minor axis)  Lateral torsional buckling  Torsional buckling (Indian & Euro codes)  Flexural torsional buckling (Indian & Euro codes) 8. Design checks being carried out

14 GSA Steel Member Design  Types of the results uUtilisation factors of the members uSummary of utilisation factors uBrief – detailed calculations for critical section of the member uVerbose – detailed calculation for all the sections of the member uEffective length of the members uSynopsis – summary of all steel sections used for the whole model 9. Results

15 GSA Steel Member Design  Viewing the results uContour on graphic view - utilisation factors uOutput table view – selected members & cases uFrom object viewer (for individual member) 9. Results

16 GSA Steel Member Design  Torsion not fully considered.  Only commonly used section types are covered  Welding material disregarded in assessment of section properties.  Whole structure stability issues are not considered since the steel checker only knows one member at a time. 10. Limitations