例7:ジオメトリ分解で仮想ジオメトリを使用

Virtual Geometryは、基礎となるジオメトリを変更せずにメッシュ特性を変えるために使います。次の例では、不要なSliver Curveを除去し、Sweep可能なVolumeを作るためにVirtual Geometryを使用します。Composite Curve機能で、わずかに曲がったSurfaceをWebcutしたときにできるSliver Curveをまとめます。続いてPartition SurfaceコマンドでSurfaceに追加Partitionを作成し、Sweep可能性を確保します。

推奨Webcut

Webcut コマンド

CUBIT> webcut volume 1 sweep surface 2 vector 0 0 -1 through_all

CUBIT> webcut volume 3 sweep surface 108 vector 0 0 -1 through_all

CUBIT> webcut volume 3 sweep surface 13 vector 0 0 -1 through_all

CUBIT> webcut volume 3 sweep surface 28 vector 0 0 -1 through_all

CUBIT> webcut volume 3 sweep surface 74 vector 0 0 -1 through_all

CUBIT> webcut volume 3 with sheet extended from surface 197

CUBIT> webcut volume 8 with sheet extended from surface 224

CUBIT> webcut volume 11 10 12 9 with plane surface 28

CUBIT> webcut volume 3 with plane normal to curve 116 fraction 0.5

CUBIT> webcut volume 3 17 with plane normal to curve 835 close_to vertex 487

CUBIT> webcut volume 18 19 with sheet extended from surface 376

CUBIT> webcut volume 3 17 with sheet extended from surface 378

CUBIT> webcut volume 8 with sheet extended from surface 73

CUBIT> webcut volume 8 with sheet extended from surface 72

CUBIT> webcut volume 8 with sheet extended from surface 133

CUBIT> webcut volume 8 with sheet extended from surface 71

CUBIT> webcut volume 8 with plane vertex 709 vertex 713 vertex 702

CUBIT> unite volume 36 45

CUBIT> unite volume 37 43

CUBIT> unite volume 35 44

CUBIT> unite volume 39 42

CUBIT> webcut volume 29 with plane vertex 81 vertex 93 vertex 154

 

CUBIT> unite volume 33 36 50 11

CUBIT> unite volume 10 49 37 31

CUBIT> unite volume 12 52 35 34

CUBIT> unite volume 9 51 39 32

CUBIT> unite volume 9 22

CUBIT> unite volume 12 23

CUBIT> unite volume 20 33

CUBIT> unite volume 21 10

CUBIT> webcut volume 12 with plane vertex 86 vertex 71 vertex 76

CUBIT> webcut volume 53 with plane vertex 738 vertex 87 vertex 741

CUBIT> webcut volume 12 with plane vertex 72 vertex 85 vertex 74

CUBIT> webcut volume 55 with plane vertex 754 vertex 205 vertex 208

CUBIT> webcut volume 12 sweep surface 731 along curve 1073 through_all

CUBIT> unite volume 53 57 56

CUBIT> unite volume 54 12 55

CUBIT> webcut volume 9 with plane vertex 99 vertex 101 vertex 103

CUBIT> webcut volume 58 with plane vertex 769 vertex 98 vertex 772

CUBIT> webcut volume 9 with plane vertex 106 vertex 104 vertex 100

CUBIT> webcut volume 60 with plane vertex 781 vertex 201 vertex 198

CUBIT> webcut volume 9 sweep surface 764 along curve 1078 through_all

CUBIT> unite volume 58 62 60

CUBIT> unite volume 59 9 61

CUBIT> webcut volume 20 with plane vertex 140 vertex 138 vertex 135

CUBIT> webcut volume 63 with plane vertex 139 vertex 137 vertex 134

CUBIT> webcut volume 20 with plane vertex 141 vertex 800 vertex 796

CUBIT> webcut volume 64 with plane vertex 803 vertex 220 vertex 223

CUBIT> webcut volume 63 sweep surface 803 along curve 1238 through_all

CUBIT> unite volume 20 67 66

CUBIT> unite volume 65 63 64

CUBIT> webcut volume 21 with plane vertex 165 vertex 163 vertex 160

CUBIT> webcut volume 68 with plane vertex 164 vertex 162 vertex 159

CUBIT> webcut volume 21 with plane vertex 825 vertex 169 vertex 822

CUBIT> webcut volume 69 with plane vertex 830 vertex 216 vertex 213

CUBIT> webcut volume 68 sweep surface 836 along curve 1069 through_all

CUBIT> unite volume 21 72 69

CUBIT> unite volume 70 68 71

各補強リブを図の形状になるようWebcutする手順です。各補強リブに同じ操作を繰り返します。この手順では、後でCompositeして除去する必要があるSliver Curveも生成されます。

CUBIT> webcut volume 70 65 59 54 with plane surface 2

CUBIT> unite volume 1 76 75 73 74

CUBIT> unite volume 28 47 46 41 48 38 8 30 29 40

CUBIT> webcut volume 28 with plane surface 870

CUBIT> webcut volume 28 77 with plane surface 871

CUBIT> webcut volume 28 77 with plane surface 878

CUBIT> webcut volume 28 77 with plane surface 879

CUBIT> webcut volume 1 81 2 82 with plane normal to curve 1849 fraction 0.5

CUBIT>webcut volume 19 18 with plane normal to curve 843 fraction 0.75

CUBIT> create curve vertex 1122 vertex 471 on surface 1134

CUBIT> webcut volume 19 sweep curve 2073 along curve 2042 through_all

CUBIT> webcut volume 18 with sheet extended from surface 1146

CUBIT> webcut volume 18 with sheet extended from surface 1135

CUBIT> unite volume 91 92

CUBIT> delete curve 2073

CUBIT> unite volume 89 18

CUBIT> unite volume 88 19

CUBIT> imprint all

CUBIT> merge all

Webcutでできた短いCurveをComposite

CUBIT> composite create curve 1456 1468

CUBIT> composite create curve 1459 1467

CUBIT> composite create curve 1499 1511

CUBIT> composite create curve 1502 1510

CUBIT> composite create curve 1371 1379

CUBIT> composite create curve 1370 1381

CUBIT> composite create curve 1423 1413

CUBIT> composite create curve 1422 1414

CUBIT> volume all scheme auto

既存Vertexを使って図のPartitioned Curveを作成

CUBIT> partition create surface 1067 vertex 311 175

CUBIT> partition create surface 1067 vertex 174 312

CUBIT> partition create surface 1063 vertex 123 294

CUBIT> partition create surface 1251 vertex 170 226

CUBIT> partition create surface 1082 vertex 195 115

CUBIT> partition create surface 1082 vertex 242 116

CUBIT> partition create surface 1077 vertex 117 309

CUBIT> partition create surface 1255 vertex 118 310

この例ではメッシュ生成順序が重要です。VolumeをメッシュするとCurveとSurfaceの分割数が固定されるため、隣接Volume間ですべての分割数を一致させる必要があります。通常はメッシュアルゴリズムが分割数の整合を処理しますが、Volumeを特定の順序でメッシュした方がよい場合があります。この例では、メッシュ順序によって最終メッシュ品質も大きく変わります。

CUBIT> reset volume all

CUBIT> volume all scheme auto

CUBIT> volume 81 scheme sweep source surface 979 target surface 1061 rotate off

CUBIT> volume 81 sweep smooth auto

CUBIT> volume 85 scheme sweep source surface 1061 target surface 889 rotate off

CUBIT> volume 85 sweep smooth auto

CUBIT> volume all size 0.1

CUBIT> curve 2125 2122 interval 12

CUBIT> mesh vol 5 6 7 13 14 15 16 (COLORED GREEN)

CUBIT> mesh Volume 85 81 77 83 78 82 87 28 80 79 (COLORED RED)

CUBIT> mesh vol 88 89 91 90 17 3 (COLORED YELLOW)

CUBIT> mesh volume with not is_meshed (COLORED WHITE)

最終メッシュ

最終メッシュを以下に示します。