<div dir="ltr">Hello everyone,<div><br></div><div>Fortunately I am able to solve this problem. Thanks to Salome (<a href="http://www.salome-platform.org/forum/forum_10/984341982">http://www.salome-platform.org/forum/forum_10/984341982</a>) from which I took reference and able to mesh the sphere with only hexahedral mesh in gmsh. The code for meshing a hollow sphere with only hexahedral elements is given below:</div><div><div>a = 1/Sqrt(3);</div><div>b = 2/Sqrt(3);</div><div><br></div><div>Point(1) = {0, 0, 0, 0.1};</div><div>Point(2) = {1, 0, 0, 0.1};</div><div>Point(3) = {2, 0, 0, 0.1};</div><div>Point(4) = {0, 1, 0, 0.1};</div><div>Point(5) = {0, 2, 0, 0.1};</div><div>Point(6) = {0, 0, 1, 0.1};</div><div>Point(7) = {0, 0, 2, 0.1};</div><div>Point(8) = {Cos(Pi/4),Cos(Pi/4),0, 0.1}; <span class="" style="white-space:pre"> </span>// XY Plane inner sphere</div><div>Point(9) = {2*Cos(Pi/4),2*Cos(Pi/4),0, 0.1};<span class="" style="white-space:pre"> </span>// XY Plane outer sphere</div><div>Point(10) = {0, Cos(Pi/4),Cos(Pi/4),0.1}; <span class="" style="white-space:pre"> </span>// YZ Plane inner sphere</div><div>Point(11) = {0, 2*Cos(Pi/4),2*Cos(Pi/4),0.1}; <span class="" style="white-space:pre"> </span>// YZ Plane outer sphere</div><div>Point(12) = {Cos(Pi/4), 0,Cos(Pi/4),0.1}; <span class="" style="white-space:pre"> </span>// XZ Plane inner sphere</div><div>Point(13) = {2*Cos(Pi/4), 0, 2*Cos(Pi/4),0.1}; <span class="" style="white-space:pre"> </span>// XZ Plane outer sphere</div><div>Point(14) = {a, a, a, 0.1};</div><div>Point(15) = {b, b, b, 0.1};</div><div><br></div><div>Line(1) = {2, 3};</div><div>Line(2) = {4, 5};</div><div>Line(3) = {6, 7};</div><div>Line(4) = {8, 9};</div><div>Line(5) = {10, 11};</div><div>Line(6) = {12, 13};</div><div>Circle(7) = {2, 1, 12};</div><div>Circle(8) = {12, 1, 6};</div><div>Circle(9) = {6, 1, 10};</div><div>Circle(10) = {10, 1, 4};</div><div>Circle(11) = {4, 1, 8};</div><div>Circle(12) = {8, 1, 2};</div><div>Circle(13) = {3, 1, 13};</div><div>Circle(14) = {13, 1, 7};</div><div>Circle(15) = {7, 1, 11};</div><div>Circle(16) = {11, 1, 5};</div><div>Circle(17) = {5, 1, 9};</div><div>Circle(18) = {9, 1, 3};</div><div>Circle(19) = {12, 1, 14};</div><div>Circle(20) = {14, 1, 8};</div><div>Circle(21) = {14, 1, 10};</div><div>Circle(22) = {13, 1, 15};</div><div>Circle(23) = {15, 1, 9};</div><div>Circle(24) = {15, 1, 11};</div><div>Line(37) = {14, 15};</div><div><br></div><div>Line Loop(25) = {16, -2, -10, 5};</div><div>Plane Surface(26) = {25};</div><div>Line Loop(27) = {15, -5, -9, 3};</div><div>Plane Surface(28) = {27};</div><div>Line Loop(29) = {2, 17, -4, -11};</div><div>Plane Surface(30) = {29};</div><div>Line Loop(31) = {4, 18, -1, -12};</div><div>Plane Surface(32) = {31};</div><div>Line Loop(33) = {3, -14, -6, 8};</div><div>Plane Surface(34) = {33};</div><div>Line Loop(35) = {6, -13, -1, 7};</div><div>Plane Surface(36) = {35};</div><div>Line Loop(38) = {22, -37, -19, 6};</div><div>Plane Surface(39) = {38};</div><div>Line Loop(40) = {37, 23, -4, -20};</div><div>Plane Surface(41) = {40};</div><div>Line Loop(42) = {24, -5, -21, 37};</div><div>Plane Surface(43) = {42};</div><div>Line Loop(44) = {21, -9, -8, 19};</div><div>Ruled Surface(45) = {44};</div><div>Line Loop(46) = {21, 10, 11, -20};</div><div>Ruled Surface(47) = {46};</div><div>Line Loop(48) = {19, 20, 12, 7};</div><div>Ruled Surface(49) = {48};</div><div>Line Loop(50) = {22, 24, -15, -14};</div><div>Ruled Surface(51) = {50};</div><div>Line Loop(52) = {13, 22, 23, 18};</div><div>Ruled Surface(53) = {52};</div><div>Line Loop(54) = {23, -17, -16, -24};</div><div>Ruled Surface(55) = {54};</div><div><br></div><div>Surface Loop(56) = {53, 36, 32, 49, 41, 39};</div><div>Volume(57) = {56};</div><div>Surface Loop(58) = {51, 28, 45, 34, 43, 39};</div><div>Volume(59) = {58};</div><div>Surface Loop(60) = {30, 26, 55, 47, 43, 41};</div><div>Volume(61) = {60};</div><div><br></div><div>Transfinite Line {1,2,3,4,5,6,37} = 6 Using Progression 1;</div><div>Transfinite Line {9,12,15,18,19,22} = 6 Using Progression 1;</div><div>Transfinite Line {20,21,23,24,10,11,16,17,7,8,13,14} = 7 Using Progression 1;</div><div><br></div><div>Transfinite Surface {26,28,30,32,34,36,39,41,43,45,47,49,51,53,55};</div><div>Recombine Surface {26,28,30,32,34,36,39,41,43,45,47,49,51,53,55};</div><div><br></div><div>Transfinite Volume {57,59,61};</div><div>Recombine Volume {57,59,61};</div><div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, May 31, 2016 at 1:49 PM, Rahul Sharma <span dir="ltr"><<a href="mailto:rsh891@gmail.com" target="_blank">rsh891@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hello,<div><br></div><div>I am trying to mesh 1/8th of a hollow sphere which consists of three plane surfaces and two ruled surfaces, I am trying to get a mesh with all quads and 8-node Hexahedron elements however when I use transfinite surface and recombine surface and volume command ,tip of the sphere section is converted into prism elements that is what I don't want. </div><div><br></div><div>Please take a look at the geo file </div><div><br></div><div><div>Point(1) = {0, 0, 0, 1};</div><div>Point(2) = {1, 0, 0, 1};</div><div>Point(3) = {2, 0, 0, 1};</div><div>Point(4) = {0, 1, 0, 1};</div><div>Point(5) = {0, 2, 0, 1};</div><div>Point(6) = {0, 0, 1, 1};</div><div>Point(7) = {0, 0, 2, 1};</div><div><br></div><div>Line(1) = {4, 5};</div><div>Line(2) = {2, 3};</div><div>Line(3) = {6, 7};</div><div>Circle(4) = {5, 1, 3};</div><div>Circle(5) = {3, 1, 7};</div><div>Circle(6) = {5, 1, 7};</div><div>Circle(7) = {4, 1, 2};</div><div>Circle(8) = {2, 1, 6};</div><div>Circle(9) = {4, 1, 6};</div><div><br></div><div>Line Loop(10) = {6, -3, -9, 1};</div><div>Plane Surface(11) = {10};</div><div>Line Loop(12) = {1, 4, -2, -7};</div><div>Plane Surface(13) = {12};</div><div>Line Loop(14) = {3, -5, -2, 8};</div><div>Plane Surface(15) = {14};</div><div>Line Loop(16) = {9, -8, -7};</div><div>Ruled Surface(17) = {16};</div><div>Line Loop(18) = {6, -5, -4};</div><div>Ruled Surface(19) = {18};</div><div><br></div><div>Surface Loop(20) = {19, 11, 15, 13, 17};</div><div>Volume(21) = {20};</div><div><br></div><div>Transfinite Line{1:3} = 3 Using Progression 1;</div><div>Transfinite Line{4,6,7,9} = 6 Using Progression 1;</div><div>Transfinite Line{5,8} = 7 Using Progression 1;</div><div><br></div><div>Transfinite Surface{11,13,15,17,19};</div><div>Recombine Surface{11,13,15,17,19};</div><div><br></div><div>Transfinite Volume{21};</div><div>Recombine Volume{21};</div><div><br></div><div>--------------------------------------</div><div>The mesh I want is similar to this (<a href="http://res.cloudinary.com/engineering-com/image/upload/v1437412966/tips/Mesh_Sphere_h01ftf.jpg" target="_blank">http://res.cloudinary.com/engineering-com/image/upload/v1437412966/tips/Mesh_Sphere_h01ftf.jpg</a>). </div><div><br></div><div>Looking forward to your comments. Thanks in advance.</div><span class="HOEnZb"><font color="#888888"><div><br></div>-- <br><div data-smartmail="gmail_signature"><div dir="ltr"><div>Warm Regards,</div><div><br></div><div dir="ltr"><b>Rahul Sharma</b><div>Graduate Student </div><div>Structural Optimization and computaion mechanics</div><div>Delft University of Technology</div><div>Netherlands</div><div><br></div></div></div></div>
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</blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div>Warm Regards,</div><div><br></div><div dir="ltr"><b>Rahul Sharma</b><div>Graduate Student </div><div>Structural Optimization and computation mechanics</div><div>Delft University of Technology</div><div>Netherlands</div></div></div></div>
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