ABAQUS Advanced use Element and Node SetsShear Locking in solid elementsReduced Integration and Zero Energy ModesSign ConventionIntegration SchemesShell Elements pitfalls to avoidBeam ElementsGeneral Suggestions

ABAQUS CAE - ModulesPART Create part using SketcherSKETCH sketcherASSEMBLY Creation of instances and assembly.PROPERTY Define Material, SECTION Properties and ASSIGNS it. STEP Analysis StepsINTERACTION Interaction Properties, Constraints. Contact between 2 surfaces,LOAD Loads, Boundary Conditions and Fields.MESH Choice of element JOB Creates Job, associates job with a MODELVISUALIZATION Post processing

Sign ConventionDisplacements and point loads are positive in the direction of the positive axes.Normal Stresses Tensile stress is +ve.Shear stress anticlockwise about element centre is +ve.Direct strains Tensile stress is +veSoils consolidation s = s + u

Stress DiscontinuitiesStresses are calculated accurately at Gauss (Integration) points.Displacements are continuous across element boundaries.Stresses jump across element boundaries.

Shell Element - NormalThe direction of the +ve normal is defined by the nodal sequence and the Right hand rule.The section points are numbered in the direction of the +ve normal. The section points identify the sections.

Parts and InstancesParts are the master components. These are not directly assembled. Instances are the copies of parts which make up the assembly.In the plate example the plate is the only part and is named Part-1Instance is a copy of the Part. It is the instances which form the assembly. If there is only a single part then the assembly consists of just the instance of the single part.

What is the need for Instances? One might ask why there is a need for instances? Why not just have part (or parts) Which are assembled into the assembly?Instance in addition to containing all the information of the Part has information about its positioning in the assembly (using a translation and rotation vector). If the assembly contains multiple copies of a component (Part) then this is facilitated by having multiple instances of the part.

Example of Instance *Part, name=L-Plate*Node 1, 15., 0., 30. 2, 15., 0., 0. *Element, type=C3D8R 1, 577, 404, 461, 576, 2417, 2244, 2301, 2416 .*End part..**** ASSEMBLY***Assembly, name=Assembly** *Instance, name=L-Plate-1, part=L-Plate*End Instance** *Instance, name=L-Plate-2, part=L-Plate 65., 30., 0. 65., 30., 0., 65., 30., 1., 180.*End Instance**

Example of Instance *Part, name=L-Plate*Node 1, 15., 0., 30. 2, 15., 0., 0. *Element, type=C3D8R 1, 577, 404, 461, 576, 2417, 2244, 2301, 2416 .*End part..**** ASSEMBLY***Assembly, name=Assembly** *Instance, name=L-Plate-1, part=L-Plate*End Instance** *Instance, name=L-Plate-2, part=L-Plate 65., 30., 0. 65., 30., 0., 65., 30., 1., 180.*End Instance**

Parts and InstancesBy default instances are dependent entities. Instances then inherit all the properties from the part (Example : mesh section and material properties).However it is possible to make the instance independent when the instance is created. Then the instance can be meshed separately and assigned properties independent of the part. (Example : two parts have minor differences).