调用示例

AMCAX_API double ComputeQuality(const NMMeshElem        &elem,
                                const QualityType        qtye,
                                const CommercialSoftware cstye);

参数类型说明

NMMeshElem

单元类型为线性单元，包括三角形、四边形、四面体、金字塔、棱柱、六面体。

Tri_3

Quad_4

Tet_4

Pyramid_5

Prism_6

Hex_8

QualityType

质量指标包括大部分商软中的质量指标，具体为：

MinLength	最小长度	MaxLength	最大长度	MinHeight	最小高度	MinNormalizedHeight	最小标准高度
CharacteristicLength	特征长度	ElementQuality	ANSYS中的单元质量	SkewnessByVolume	基于体积的扭曲度	SkewnessByEquiangular	基于角度的扭曲度
MaxAngle2d	二维最大夹角	MinAngle2d	二维最小夹角	JacobianRatioByCorner	基于交点的雅克比比率	JacobianRatioByGauss	基于高斯点的雅克比比率
AspectRatio	横纵比	Collapse	坍塌值	WarpingAngle	翘曲角	WarpingFactor	翘曲因子
ChordalDeviation	弦差	Taper	锥度	MaxDihedraAngle	最大二面角	MinDihedraAngle	最小二面角

CommercialSoftware

商软类型包括具有独立质量指标计算方式的商软，具体为：HyperMesh、ANSYS、Fluent、Nastran。

HyperMesh

ANSYS

Fluent

Nastran

指标类型

以下为各个质量指标的最优/最差的值：

质量指标	[最差, 最优]
Skewness (angle)	[90°, 0°]
Skewness (value)	[1, 0]
Jacobian	[-1, 1]
Aspect Ratio	[inf, 1]
Warping (angle)	[pi, 0]
Warping factor (value)	[inf, 0]
Interior Angles	Tri: Max angle: [180°, 60°] Min angle: [0°, 60°] Quad: Max angle: [180°, 90°] Min angle:[0°, 90°]
Collapse	[0, 1]
Taper	[1, 0]
Element Quality	[0, 1]

商业指标对照表

HyperMesh (Shells)
Aspect Ratio	Skew	Chordal Deviation	Warpage	Tri minimum angle	Tri maximum angle	Quad minimum angle	Quad maximum angle	Minimum length	Maximum length

HyperMesh (Solid)
Aspect Ratio	Skew	Volumetric Skewness	Jacobian	Tet collapse	Equia skew	Minimum angle	Maximum angle	Minimum length

ANSYS (Shells)
Aspect Ratio	Skewness	Warping	Jacobian	Minimum angle	Maximum angle	Characteristic Length	Minimum length	Element Quality	Parallel Deviation

ANSYS (Solid)
Aspect Ratio	Warping	Jacobian	Collapse	Characteristic Length	Min Height	Element Quality	Parallel Deviation

Fluent (Shells)
Aspect Ratio	Skewness	Warp

Fluent (Solid)
Aspect Ratio	Skewness	Warp	Dihedral Angle

Nastran (Shells)
Aspect Ratio	Skewness	Warping	Taper	Jacobian	Minimum angle	Maximum angle	Characteristic Length	Minimum length

Nastran (Solid)
Aspect Ratio	Warping	Jacobian	Collapse	Characteristic Length	Min Height

完整示例

以下是一个完整的示例，说明如何获取生成网格中二维三角形面网格的面积偏斜度和三维四面体体网格的体积偏斜度，基于 Fluent 商业软件进行分析：

#include <fstream>
#include <nlohmann/json.hpp>
#include <nextmesh/NMAPIModel.hpp>
#include <set>
#include <step/StepDataTool.hpp>
 
using namespace AMCAX::NextMesh;
 
void Quality()
{
    const std::string cadstr = "./data/test.step";
    const std::string jsonPath = "./data/test.json";
 
    NMAPIModel nmapi;
    NMAPIModel::InitLogger();
    AMCAX::TopoShape step_shape;
    AMCAX::STEP::StepDataTool::Read(step_shape, cadstr);
    nmapi.ImportModel({ step_shape });
 
    std::vector<NMEntity> ent_d2, ent_d3;
    nmapi.GetEntities(ent_d2, DimType::D2);
    nmapi.GetEntities(ent_d3, DimType::D3);
 
    nlohmann::json paraJ = nlohmann::json::parse(std::ifstream(jsonPath));
    nmapi.GenerateMesh(paraJ.dump());
    auto meshapi = nmapi.GetMesh();
 
    for (auto entf : ent_d2)
    {
        auto ec = meshapi.EntityGetElementCount(entf);
        for (size_t i = 0; i < ec; i++)
        {
            auto elem = meshapi.EntityGetElementByIndex(entf, i);
            double quality = 1.0;
            if (meshapi.ElementGetType(elem) == ElemType::Tri_3)
            {
                quality = meshapi.ComputeQuality(
                    elem,
                    QualityType::SkewnessByVolume,
                    CommercialSoftware::Fluent
                );
            }
        }
    }
 
    for (auto entf : ent_d3)
    {
        auto ec = meshapi.EntityGetElementCount(entf);
        for (size_t i = 0; i < ec; i++)
        {
            auto elem = meshapi.EntityGetElementByIndex(entf, i);
            double quality = 1.0;
            if (meshapi.ElementGetType(elem) == ElemType::Tet_4)
            {
                quality = meshapi.ComputeQuality(
                    elem,
                    QualityType::SkewnessByVolume,
                    CommercialSoftware::Fluent
                );
            }
        }
    }
}

点击这里example04可获得网格质量示例完整源码，大家根据学习需要自行下载。