Expand IntroductionIntroduction
Expand AdministrationAdministration
Expand User InterfaceUser Interface
Expand SolidWorks FundamentalsSolidWorks Fundamentals
Expand Moving from 2D to 3DMoving from 2D to 3D
Expand AssembliesAssemblies
Expand CircuitWorksCircuitWorks
Expand ConfigurationsConfigurations
Expand SolidWorks CostingSolidWorks Costing
Expand Design CheckerDesign Checker
Expand Design Studies in SolidWorksDesign Studies in SolidWorks
Expand Detailing and DrawingsDetailing and Drawings
Expand DFMXpressDFMXpress
Expand DriveWorksXpressDriveWorksXpress
Expand FloXpressFloXpress
Expand Import and ExportImport and Export
Expand Model DisplayModel Display
Expand Mold DesignMold Design
Expand Motion StudiesMotion Studies
Expand Parts and FeaturesParts and Features
Expand RoutingRouting
Expand Sheet MetalSheet Metal
Collapse SimulationSimulation
Welcome to SolidWorks Simulation Help
Accessing and Using Help
Legal Notices
SolidWorks Simulation Reference
Expand SolidWorks Simulation FundamentalsSolidWorks Simulation Fundamentals
Expand Analysis BackgroundAnalysis Background
Expand Simulation OptionsSimulation Options
Expand Simulation StudiesSimulation Studies
Expand Submodeling StudiesSubmodeling Studies
Expand Design StudiesDesign Studies
Expand 2D Simplification Studies2D Simplification Studies
Expand Composite ShellsComposite Shells
Expand Loads and RestraintsLoads and Restraints
Expand Background on MeshingBackground on Meshing
Expand Meshing with ContactMeshing with Contact
Expand Simulation MaterialsSimulation Materials
Expand ParametersParameters
Expand Analysis Library FeaturesAnalysis Library Features
Collapse Viewing Analysis ResultsViewing Analysis Results
Collapse Plotting ResultsPlotting Results
Acceleration Plot PropertyManager
Beam Diagrams PropertyManager
Design Insight PropertyManager
Displacement Plot PropertyManager
Fatigue Plot PropertyManager
Expand Strain Plot PropertyManagerStrain Plot PropertyManager
Strain Energy Density Plot PropertyManager
Collapse Stress Plot PropertyManagerStress Plot PropertyManager
Stress Components
Beam Stress Components
Principal Stresses Definition
Plotting Principal Stresses
Stress Averaging Across Common Part Boundaries
Expand Thermal Plot PropertyManagerThermal Plot PropertyManager
Velocity Plot PropertyManager
Expand Listing ResultsListing Results
Expand Graphing ResultsGraphing Results
Expand Processing Result PlotsProcessing Result Plots
Expand Compare Test DataCompare Test Data
Expand Simulation Data SensorsSimulation Data Sensors
Expand Probing Result PlotsProbing Result Plots
Expand Study ReportsStudy Reports
Expand Factor of Safety CheckFactor of Safety Check
Expand SimulationXpressSimulationXpress
Expand SketchingSketching
Expand Sustainability ProductsSustainability Products
Expand SolidWorks UtilitiesSolidWorks Utilities
Expand TolerancingTolerancing
Expand TolAnalystTolAnalyst
Expand ToolboxToolbox
Expand WeldmentsWeldments
Expand Workgroup PDMWorkgroup PDM
Expand TroubleshootingTroubleshooting
Hide Table of Contents

Principal Stresses Definition

The state of stresses at a point is completely defined by normal and shear stress components in reference to an orthogonal coordinate system XYZ. In general, the values of the stress components change if the coordinate system is rotated.

At a certain orientation (X’Y’Z’), all shear stresses vanish and the state of stresses is completely defined by 3 normal stress components.

These 3 normal stress components are referred to as principal stresses and the corresponding reference axes (X’Y’Z’) are referred to as principal axes.

Figure 1 Figure 2

At certain orientation of the material element shown in Figure 1, the shear stress components vanish, and stresses reduce to pure normal stresses as shown in Figure 2.

You can plot all 3 components at once. The principal stresses at a node or element center are represented by an ellipsoid. The 3 radii of the ellipsoid represent the magnitudes of the 3 principal stresses. The direction of the stress (tension/compression) is represented by arrows. The color code is based on the von Mises stress values, a scalar quantity.

If the three principal stresses have the same magnitude, the ellipsoid becomes a sphere (Figure 3). If one of the principal stresses is zero, the ellipsoid becomes a planar ellipse (Figure 4). In the case of simple uniaxial stress, the ellipsoid becomes a line.
Figure 3. Three equal principal stresses in tension. The ellipsoid becomes a sphere. Figure 4. One of the principal stresses is very small.

Provide feedback on this topic

SOLIDWORKS welcomes your feedback concerning the presentation, accuracy, and thoroughness of the documentation. Use the form below to send your comments and suggestions about this topic directly to our documentation team. The documentation team cannot answer technical support questions. Click here for information about technical support.

* Required

Subject:   Feedback on Help Topics
Page:   Principal Stresses Definition
*   I acknowledge I have read and I hereby accept the privacy policy under which my Personal Data will be used by Dassault Systèmes

Print Topic

Select the scope of content to print:


We have detected you are using a browser version older than Internet Explorer 7. For optimized display, we suggest upgrading your browser to Internet Explorer 7 or newer.

 Never show this message again

Web Help Content Version: SOLIDWORKS 2013 SP05

To disable Web help from within SOLIDWORKS and use local help instead, click Help > Use SOLIDWORKS Web Help.

To report problems encountered with the Web help interface and search, contact your local support representative. To provide feedback on individual help topics, use the “Feedback on this topic” link on the individual topic page.