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GSA 8.6 – New Features


64-bit edition



GSA 8.6 – 64-bit hardware support

• New 64-bit edition of GSA• 32-bit edition remains available

• Improved handling of large models

• Utilises (effectively) unlimited RAM• 264 = 18,446,744,073,709,551,616• (232 = 4,294,967,296)

• Side effects• OpenGL viewports• Graphics selection• (resolved by updating graphics driver in most cases)

• Licensing


Steel Design



GSA 8.6 – Steel Design Codes

New steel design codes:

• AISC360:05

• AISC360:10

• AS4100:98

• HKSUOS:05

• EN 1993-1-1:2005 Eurocode 3 (NL)

• EN 1993-1-1:2005 Eurocode 3 (FR)


GSA 8.6 – Steel Design of Channels and Tees

• Steel design may now be carried out for Channel and Tee sections

• This is available for all supported codes


Seismic Analysis



GSA 8.6 – Seismic codes

• Response spectra supported now include:• ASCE 7-10 (USA)• GB50011-2010 (China)

• Equivalent static analysis extended to more support more codes:• ASCE 7, Eurocode 8, FEMA 356, GB50011, IBC, IS 1893,

UBC 97

• Response spectrum analysis now has a fast or rigorous option• Fast – only combines responses where coupling

coefficient is significant – reducing the number of calculations when there are a large number of modes


2D Load Panel Elements



GSA 8.6 – 2D Load Panel Elements

• Non-structural 2D elements that transfer load to surrounding beam elements

• Load distribution options:• All edges supported• Three edges supported• Two edges supported• Two adjacent edges supported• One edge supported• Cantilever support

• Useful for applying wind loads


GSA 8.6 – 2D Load Panel Elements

• Limitations• Will give force equilibrium...

... but may not give moment equilibrium (one edge supported)• Can only be used for uniform pressure over the element• Load panel must be bounded by beam (bar) elements

(can be dummy elements)• Dummy elements cannot be loaded – different load

pattern must be selected• Can be problems if warped


GSA 8.6 – Cladding tool

• Generates load panel elements

• Convenient for ‘cladding’ a structure for the application of wind loads

• Can be caught out by complex topologies

• (Implemented to contribute to the GsWind ‘Wind loading Automation for GSA’ development, funded by others)



• Start with frame model




• Create list of exterior elements & select





• Use ‘Create Load Panels on Surface’






• Add cladding to model






• Add cladding to model

• Clad model


2D Element Thickness Modifiers



GSA 8.6 – Thickness Modifiers on 2D Elements

• New modifier for mass/weight calculations• Includes gravity loading

• Clarification of thickness used for 2D element results• In-plane forces (Nx, Ny, Nxy) based on in-plane thickness

• Moments (Mx, My, Mxy) based on bending thickness

• Through thickness shear (Qx, Qy) based on bending thickness• Stresses (σxx, σyy, σzz, σxy, σyz, σzx) based on actual

thickness


Wall Element



GSA 8.6 – Wall Element

• Super-elements represented internally by 4-by-4 Quad8 shell elements.

• Wall results are represented on an equivalent beam, or ‘wall stick’, in either direction

• Equivalent beam results can be tabulated, and displayed as contours and diagrams • Forces/moments & stresses



• A large 2D element/super-element represented internally by 4×4 Quad8 shell elements

• Wall results are represented on an equivalent beam or ‘wall stick’ in either primary or secondary direction, i.e. wall elements results at the 4 edges

• Wall element nodes have rotational stiffness about the normal direction of the wall elements• But with limitations



Topology 1 Topology 2


A wall element

Edge 1

Edge 2

Edge 3

Edge 4





Equivalent beams in results output

Primary

Sec

on

dar

y



Topo 1 Topo 2

Topo 4 Topo 3

Generation of drilling stiffness

Edge 1

Edge 2

Edge 3

Edge 4



Generation of drilling stiffness

Dummy/slave node to the edge nodes

Same vertical displacement

Same horizontal displacement

Stiff beam with in-plane bending & shear stiffness only, pinned at dummy node end and fixed at corner node end



• Known limitations in this version of GSA• Wall element must be rectangular• Wall elements can only be used for linear static, modal

dynamic and response spectrum analysis• Grouped wall element results are not available• Cut section forces are not available• Other elements can only connected to the wall elements

through the 4 nodes• Only equivalent beam results (wall edge results) are

available, it is not appropriate to use wall to model slab at the moment• Drilling stiffness is underestimated if the connected beam

section size is larger than 1/8 of the wall element size


2D Elements with ‘zz’ Stiffness



GSA 8.6 – 2D Linear Element with ‘zz’ Rotational Stiffness

• ‘Drilling’ degree of freedom• Bilinear: x, y, z, xx, yy• Allman-Cook: x, y, z, xx, yy, zz

• Useful because:• Practically Avoids use of automatic constraints

• Numerically Reduces in-plane shear locking - better approximations

• Caution because:

Not reliable for connecting beam elementsdirectly through a single point connection


GSA 8.6 – 2D Linear Element with ‘zz’ Rotational Stiffness

Example


Torsion Constant for Perimeter Sections



GSA 8.6 – Torsion Constant ‘J’ for Perimeter Sections

• Works (almost) like any other section property• Calculated in the Section Wizard

• Uses a new solver based on BEM

• Restricted to thick-walled sections only• Warning if walls are

too thin

• To be extended to thin-walled sections in the future


GSA 8.6 – Torsion Constant ‘J’ for Perimeter Sections

BEM solution


Solvers



GSA 8.6 – GSS Improvements

• Parallel sparse direct solver • New linear analysis solution method• Exploits multi-cores• Significantly speeds up the stiffness matrix factorisation • (But only marginal reduction in overall analysis time)

• New eigensolver• Uses shifting & locking to improve convergence• Up to 10× faster

• New solution option – Model Stability• Analysis of the stiffness of the structure• Identify unrestrained or overly flexible parts of the

structure

• Other improvements• Improved stiffness matrix assembly


GSA 8.6 – GSS Improvements

• Condition number estimation• The condition number indicates maximum possible error

in the displacements while solving a linear system• A high condition number can imply results cannot be

trusted• A model with condition number > 1016 is almost singular• Cause of high condition numbers can be investigated

using the Model Stability analysis

• High condition numbers if• Model is unrestrained• Part of the model is unrestrained• Part of the model is too flexible


GSA 8.6 – Batch Analysis Auto-save

• When ‘Tools | Preferences | Miscellaneous | Save file after batch analysis’ is set, and

• ‘Analysis | Batch Analysis’ is set,

• The file is saved automatically following a successful analysis


GSA COM



GSA 8.6 – COM interface enhancements

• GwaCommand ‘GET_ALL’ returns whole module

• Output_Arr function returns array of results

• New view functions to manipulate saved views

• EntitiesInList returns array of entities in list

• NodeConnectedEnt returns array of entities connected at a node


2D Element Centre Only Results



GSA 8.6 – Results at 2D Element Centres Only

• Option to calculate results at element centres only• To reduce file size• and memory


GSA 8.6 – Results at 2D Element Centres Only

• Options to display results at element centres only• To reduce post-processing, especially in RC slab design• Whether or not results are stored at nodal positions

• Contours and diagrams

• Element user module ‘CENTRE_ONLY_2D’ flag


Miscellaneous



GSA 8.6 – File I/O and Non-numeric Values

• GSA checks for valid numerical values when reading the file

• Invalid numerical values in tables are dispalyed as #### (previously -1 until editing field)

• Preference to check file versions when reading – gives warning of file written by a different version of GSA and therefore possible compatibility issues.

• Save is disabled after saving until model is modified.


GSA 8.6 – Incomplete Entities

• Option in Elements/Member tables to identify incomplete entities• Red – reference to non-existant entitiy• Blue – repeated entity


GSA 8.6 – Edge load on 2D Elements

• Edge loads can now be applied as• A pressure on the edge (original option)• A force per unit length


GSA 8.6 – Constraint Stage Lists

• Constraints may now be specified as applying to a list of stages

• Generalised restraints, rigid constraints, joints, constraints and tied interfaces


GSA 8.6 – Load Names

• Names may now be given to loading records• Only visible in load tables if the 'Input | Show names in

loads tables' preference is selected


GSA 8.6 – Spreadsheet Interaction

• ‘Fully populate fields’ Output Setting


GSA 8.6 – Spreadsheet Interaction

• ‘Fully populate fields’ Output Setting• Useful when used with Excel 'Filter' and 'PivotTable'

features


GSA 8.6 – Misc. Output Options

• Beam Section Extended Properties:

• Grid plane areas reported in Grid Planes output

• Case list now recognised in:• Mass Details; Dynamic Details; Dynamic Summary;

Buckling Details; Response Spectrum Details


GSA 8.6 – Graphic View Selection Options

• Option to select all elements with same property or group or material


GSA 8.6 – Sculpt – Split At Plane

• Sculpt option to split 1D entities at intersection with plane


GSA 8.6 – Sculpt – Align Elements

• Sculpt element alignment options to:• ‘Align 1D Elements’ – selected 1D elements are flipped

such that the element x axes point generally in current grid axis directions• ‘Align 2D Element Edges’ – selected 2D elements are

spun such that the first edges align generally with specified axes• ‘Align 2D Element Z Axes ’ – selected 2D elements are

flipped such that the element z axes point generally in current grid axis directions


GSA 8.6 – Sculpt – Connect Column to Slab

• Sculpt option to connect columns to slabs


GSA 8.6 – Sculpt – Connect Column to Slab

• Sculpt option to connect columns to slabs• Uses rigid constraints• To transfer rotational stiffness


Interface with Third Party Software



GSA 8.6 – Interface with BIM

• The GSA Revit link works with Revit Structure 2012

• ... and Revit Structure 2013


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Documents

edition gsa

edition of gsa

gsa development

d load panel elements

steel design gsa

surface slide

frame model slide

elements dummy elements