HyperView应力显示解释

Nodal Averaging of Elemental ResultsNodal averaging of elemental results at a node refers to the average of all the element corner results passing through that node. If no corner results are available for an element, centroidal results will be used calculate the nodal average. In the example figure below, four elements are passing through Node 400. The average results at Node 400 is equal to:when Use corner data is turned on.when Use corner data is turned off.Nodal averaging options are selected from the Averaging method drop-down menu on the Contour and Iso Value panels. The options are:•Simple•Advanced•Difference如果取none，就是对计算结果不进行光滑处理。

如果取average，有simple,advanced等几种方法，其中simple 和advance的结果差异非常小，difference的应力结果通常会比simple,advance的要大一些，一般使用simple就可以了。

取平滑和不取平滑，应力结果差别比较大，但对位移结果没有什么影响。

通常情况下，把应力结果进行光滑后，应力值会下降一些。

在实际工作中，通常都是取光滑后的应力结果，这样的结果更接近结构的真实受力。

Simple AveragingSimple averaging means that tensor and vector components are extracted and the invariants are computed prior to averaging. For components, the corresponding components from each element corner are extracted and then they are averaged. For invariants, the corresponding invariants are calculated from each tensor at the element corners and then averaged.tensors, [A2], [B1], [C3], and [D4] at four corners at Node 400.The average of the xx component at Node 400 isFor the average of an invariant such as von Mises, the von Mises value for all tensor [A2], [B1], [C3] , and [D4] are computed, then they are averaged as follows:The averaging methods for solid elements and shell elements are different.Advanced AveragingAdvanced averaging means that tensor (or vector) results are transformed into a consistent system and then each component is averaged separately to obtain an average tensor (or vector). The invariants are calculated from this averaged tensor. The consistent system can be the global or the user-defined system for solid elements. For shell elements, the consistent system is the nodal projection system, which is the projected global or user-defined system on the nodal projection plane (described in the Projection rule). In the example shown in Nodal Averaging of Elemental Results, the averaged tensor at node 400 is:Where, are tensors transformed to thereference system for corners A2, B1, C3, and D4, respectively.The components are extracted and the invariants are computed from this averaged tensor or vector .The averaging methods for solid elements and shell elements are different.The nodal difference is the difference between the maximum and minimum corner results at a node. For tensor/vector components, the corresponding components from each element corner are extracted and the difference is calculated. For invariants, the corresponding invariants are computed from each element corner and then the difference is calculated.The sign of a value is considered in the difference calculation. For example, the difference for the values, 200, 400, -100, and -500 is 900.In the example shown in Nodal Averaging of Elemental Results, the nodal difference of tensor component xx at node 400 is:WhereThe difference calculation methods for solid elements and shell elements aredifferent.corner data：If corner data is available, the Use corner data option is enabled. If you activate the option, HyperView displays color bands by interpolating available corner results within each element. A discontinuity of the result distribution across element boundaries can be seen.variationThe relative difference at a node from corresponding corner values with respect to the value range from all nodes in the selected components.If the variation in the results is smaller than the specified percentage, HyperView will average the corner results to the nodes. If the variation is larger than the specified percentage, HyperView will keep the discontinuity of the results.Element Type ReferenceSystemProjectionRuleSolid Global N/A All corresponding tensors andvectors are transformed to theglobal coordinate system and thena component or invariant isaveraged as explained above.Analysis N/A All corresponding tensors andvectors are left in their originalcoordinate system (notransformation occurs) and then acomponent or invariant is averagedas explained above. In this case,each participating element resultcan be in a differentsystem. Simple averaging forcomponents ignores variations insystems. Since invariance doesnot depend on the coordinatesystem, all reference systems willproduce the same results forinvariants.Elemental N/A All corresponding tensors andvectors are transformed to theelemental coordinate system andthen a component or invariant isaveraged as explained above. Inthis case, each participatingelement result can also be in adifferent system. Simpleaveraging for components ignoresvariations in systems. Sinceinvariance does not depend on thecoordinate system, all referencesystems will produce the sameresults for invariants.User-defined N/A All corresponding tensors andvectors are transformed to theuser-defined coordinate system andthen a component or invariant isaveraged as explained above. Shell Global ON All corresponding tensors andvectors are transformed to theprojected system (following theprojection rule) of the participatingelements and then the componentor invariants are averaged asexplained above.As a result, even if the referencesystem is the same, the projectedsystems in participating elementscan be different. Simpleaveraging for components ignoresvariations in systems.OFF All corresponding tensors andvectors are transformed to theglobal coordinate system and acomponent or invariant is thenaveraged as explained above. Analysis N/A All corresponding tensors andvectors are left in their originalcoordinate system (notransformation occurs) and then acomponent or invariant is averagedas explained above. In this case,each participating element resultcould be in a different system.Simple averaging for componentsignores variations insystems. Since invariance doesnot depend on the coordinatesystem, all reference systems willproduce the same results forinvariants.Elemental N/A All corresponding tensors andvectors are transformed to theelemental coordinate system andthen a component or invariant isaveraged as explained above. Inthis case, each participatingelement result could also be in adifferent system. Simpleaveraging for components ignoresvariations in systems. Sinceinvariance does not depend on thecoordinate system, all referencesystems will produce the sameresults for invariants.User-defined ON All corresponding tensors andvectors are transformed to theprojected system (following theprojection rule) of the participatingelements and then the componentor invariants are averaged asexplained above.As a result, even if the referencesystem is the same the projectedsystems in participating elementscan be different. Simpleaveraging for components ignoresvariations in systems.OFF All corresponding tensors andvectors are transformed to theUser-defined coordinate systemand a component or invariant isthen averaged as explained above. Valid reference coordinate system: All (Global, Analysis, Elemental, and User-defined)。