Karamba3D v3
  • Welcome to Karamba3D
  • New in Karamba3D 3.1
  • See Scripting Guide
  • See Manual 2.2.0
  • 1 Introduction
    • 1.1 Installation
    • 1.2 Licenses
      • 1.2.1 Cloud Licenses
      • 1.2.2 Network Licenses
      • 1.2.3 Temporary Licenses
      • 1.2.4 Standalone Licenses
  • 2 Getting Started
    • 2 Getting Started
      • 2.1 Karamba3D Entities
      • 2.2 Setting up a Structural Analysis
        • 2.2.1 Define the Model Elements
        • 2.2.2 View the Model
        • 2.2.3 Add Supports
        • 2.2.4 Define Loads
        • 2.2.5 Choose an Algorithm
        • 2.2.6 Provide Cross Sections
        • 2.2.7 Specify Materials
        • 2.2.8 Retrieve Results
      • 2.3 The Karamba3D Menu
      • 2.4 User Settings
      • 2.5 Physical Units
      • 2.6 Asynchronous Execution of Karamba3D Components
      • 2.7 Quick Component Reference
  • 3 In Depth Component Reference
    • 3.0 Settings
      • 3.0.1 License
    • 3.1 Model
      • 3.1.1 Assemble Model
      • 3.1.2 Disassemble Model
      • 3.1.3: Modify Model
      • 3.1.4: Connected Parts
      • 3.1.5: Activate Element
      • 3.1.6 Create Linear Element
        • 3.1.6.1 Line to Beam
        • 3.1.6.2 Line to Truss
        • 3.1.6.3 Connectivity to Beam
        • 3.1.6.4: Index to Beam
      • 3.1.7 Create Surface Element
        • 3.1.7.1: Mesh to Shell
        • 3.1.7.2: Mesh to Membrane
      • 3.1.8: Modify Element
      • 3.1.9: Point-Mass
      • 3.1.10: Disassemble Element
      • 3.1.11: Make Element-Set
      • 3.1.12: Orientate Element
      • 3.1.13: Dispatch Elements
      • 3.1.14: Select Elements
      • 3.1.15: Support
    • 3.2: Load
      • 3.2.1: General Loads
      • 3.2.2: Beam Loads
      • 3.2.3: Disassemble Mesh Load
      • 3.2.4 Load-Case-Combinations
        • 3.2.5.1 Load-Case-Combinator
        • 3.2.5.2 Disassemble Load-Case-Combinaton
        • 3.2.5.3 Load-Case-Combination Settings
    • 3.3: Cross Section
      • 3.3.1: Beam Cross Sections
      • 3.3.2: Shell Cross Sections
      • 3.3.3: Spring Cross Sections
      • 3.3.4: Disassemble Cross Section
      • 3.3.5: Eccentricity on Beam and Cross Section
      • 3.3.6: Modify Cross Section
      • 3.3.7: Cross Section Range Selector
      • 3.3.8: Cross Section Selector
      • 3.3.9: Cross Section Matcher
      • 3.3.10: Generate Cross Section Table
      • 3.3.11: Read Cross Section Table from File
    • 3.4: Joint
      • 3.4.1: Beam-Joints
      • 3.4.2: Beam-Joint Agent
      • 3.4.3: Line-Joint
    • 3.5: Material
      • 3.5.1: Material Properties
      • 3.5.2: Material Selection
      • 3.5.3: Read Material Table from File
      • 3.5.4: Disassemble Material
    • 3.6: Algorithms
      • 3.6.1: Analyze
      • 3.6.2: AnalyzeThII
      • 3.6.3: Analyze Nonlinear WIP
      • 3.6.4: Large Deformation Analysis
      • 3.6.5: Buckling Modes
      • 3.6.6: Eigen Modes
      • 3.6.7: Natural Vibrations
      • 3.6.8: Optimize Cross Section
      • 3.6.9: BESO for Beams
      • 3.6.10: BESO for Shells
      • 3.6.11: Optimize Reinforcement
      • 3.6.12: Tension/Compression Eliminator
    • 3.7 Results
      • 3.7.1 General Results
        • 3.7.1.1 ModelView
        • 3.7.1.2 Result Selector
        • 3.7.1.3 Deformation-Energy
        • 3.7.1.4 Element Query
        • 3.7.1.5 Nodal Displacements
        • 3.7.1.6 Principal Strains Approximation
        • 3.7.1.7 Reaction Forces
        • 3.7.1.8 Utilization of Elements
        • 3.7.1.9 ReactionView
      • 3.7.2 Results on Beams
        • 3.7.2.1 BeamView
        • 3.7.2.2 Beam Displacements
        • 3.7.2.3 Beam Forces
        • 3.7.2.4 Node Forces
      • 3.7.3 Results on Shells
        • 3.7.3.1 ShellView
        • 3.7.3.2 Line Results on Shells
        • 3.7.3.3 Result Vectors on Shells
        • 3.7.3.4 Shell Forces
        • 3.7.3.5 Shell Sections
    • 3.8 Export
      • 3.8.1 Export Model to DStV
      • 3.8.2 Json/Bson Export and Import
      • 3.8.3 Export Model to SAF
      • 3.8.4 Export/Import Model to and from Speckle (WIP)
    • 3.9 Utilities
      • 3.9.1: Mesh Breps
      • 3.9.2: Closest Points
      • 3.9.3: Closest Points Multi-dimensional
      • 3.9.4: Cull Curves
      • 3.9.5: Detect Collisions
      • 3.9.6: Get Cells from Lines
      • 3.9.7: Line-Line Intersection
      • 3.9.8: Principal States Transformation
      • 3.9.9: Remove Duplicate Lines
      • 3.9.10: Remove Duplicate Points
      • 3.9.11: Simplify Model
      • 3.9.12: Element Felting
      • 3.9.13: Mapper
      • 3.9.14: Interpolate Shape
      • 3.9.15: Connecting Beams with Stitches
      • 3.9.16: User Iso-Lines and Stream-Lines
      • 3.9.17: Cross Section Properties
      • 3.9.18 Surface To Truss
      • 3.9.19 Head-Up Display Legend
    • 3.10 Parametric UI
      • 3.10.1: View-Components
      • 3.10.2: Rendered View
  • Troubleshooting
    • 4.1: Miscellaneous Questions and Problems
      • 4.1.0: FAQ
      • 4.1.1: Installation Issues
      • 4.1.2: Purchases
      • 4.1.3: Licensing
      • 4.1.4: Runtime Errors
      • 4.1.5: Definitions and Components
      • 4.1.6: Default Program Settings
    • 4.2: Support
  • Appendix
    • A.1: Release Notes
      • Work in Progress Versions
      • Older Versions
      • Version 2.2.0
      • Version 2.2.0 WIP
      • Version 1.3.3
      • Version 1.3.2 build 190919
      • Version 1.3.2 build 190731
      • Version 1.3.2 build 190709
      • Version 1.3.2
    • A.2: Background information
      • A.2.1: Basic Properties of Materials
      • A.2.2: Additional Information on Loads
      • A.2.3: Tips for Designing Statically Feasible Structures
      • A.2.4: Performance Optimization in Karamba3D
      • A.2.5: Natural Vibrations, Eigen Modes and Buckling
      • A.2.6: Approach Used for Cross Section Optimization
    • A.3: Workflow Examples
    • A.4: Bibliography
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  1. 3 In Depth Component Reference
  2. 3.6: Algorithms

3.6.2: AnalyzeThII

Previous3.6.1: AnalyzeNext3.6.3: Analyze Nonlinear WIP

Last updated 7 months ago

The "Analyze ThII"-component exist for convenience. Second order theory analysis can also be specified per load-case-combination via the and calculated by an .

Section contains details regarding second order theory calculations.

In Karamba3D distinction is made between normal forces NNN which cause stresses in the members and normal forces NIIN^{II}NII which result in second order effects (see also ). At first sight this concept seems weird. How can there be two kinds of normal forces in the same beam? Well, in reality there can’t. In a computer program it is no problem: stresses get calculated as σ=N/A\sigma = N/Aσ=N/A and NIIN^{II}NII is used for determining second order effects only. The advantage is, that in the presence of several load-cases one can chose for each element the largest compressive force as NIIN^{II}NII. This gives a lower limit for the structure's stiffness. A re-evaluation of the load-cases using these NIIN^{II}NII values leads to a structural response which is too soft. However the different load-cases may then be safely superimposed.

Use the “AnalyzeThII”-component for automatically determining the normal forces NIIN^{II}NII from cross section forces Nx⋅NIIN_{x} \cdot N ^{II}Nx​⋅NIIinfluences a structure's stiffness which in turn impacts the distribution of cross section forces NxN_xNx​. Thus an iterative procedure with repeated updates of NIIN^{II}NII-forces needs to be applied.

The “AnalyzeThII”-component features the following input-plugs:

"Model"

Model to be considered

"LC"

"RTol"

"MaxIter"

"NoTenNII"

The normal forces NIIN^{II}NII get attached to the model and will be considered in all further analysis steps. They impact the results of the “Analyze”-, “Buckling Modes”-, “Natural Vibrations”- and “Optimize Cross Sections”-components. For imperfection loads NIIN^{II}NII-forces have a direct impact on the applied loads.

Use the “NII” button in submenu “Tags” of the “ModelView”-component to display NIIN^{II}NII-forces.

Fig. 3.6.2 shows the same system as in fig. . This time with results according to first and second order theory. When comparing the transverse deflections in load-case two one can see that the maximum deflection increased from 0.24[m]0.24[m]0.24[m] to 0.28[m]0.28[m]0.28[m] due to the effect of the axial compressive load.

Name of load-case or load-case-combination from which to take the normal force which cause second order theory effects. By default all the minimum normal force of all load-cases is considered. The hint in section explains how load-cases and load-case-combinations can be excluded from the default list.

The determination of is an iterative process. The value of “RTol” is the upper limit of displacement increments from one iteration to the next.

Supply here the maximum number of iterations for determining . The default is 50. In case “RTol” can not be reached within the preset number of iterations the component turns orange.

Tension forces increase the stiffness of a structure. Setting “NoTenNII” to “True” limits to negative values.

NIIN^{II}NII
NIIN^{II}NII
NIIN^{II}NII
3.5.1
NIIN^{II}NII
Load-Case-Combinations
"Load-Case-Combination Settings"-component
"Analyze"-component
3.2.5.3
[10]
37KB
AnalysisComponent_ThII.gh
Fig 3.6.2: Deflection of simply supported beam under single load in mid-span and axial compressive load