xref: /libCEED/examples/solids/qfunctions/traction-boundary.h (revision caee03026e6576cbf7a399c2fc51bb918c77f451)
1 // Copyright (c) 2017-2022, Lawrence Livermore National Security, LLC and other CEED contributors.
2 // All Rights Reserved. See the top-level LICENSE and NOTICE files for details.
3 //
4 // SPDX-License-Identifier: BSD-2-Clause
5 //
6 // This file is part of CEED:  http://github.com/ceed
7 
8 /// @file
9 /// Geometric factors for solid mechanics example using PETSc
10 
11 #ifndef TRACTION_BOUNDARY_H
12 #define TRACTION_BOUNDARY_H
13 
14 #include <ceed.h>
15 
16 // -----------------------------------------------------------------------------
17 // This QFunction computes the surface integral of the user traction vector on
18 //   the constrained faces.
19 //
20 // Reference (parent) 2D coordinates: X
21 // Physical (current) 3D coordinates: x
22 // Change of coordinate matrix:
23 //   dxdX_{i,j} = dx_i/dX_j (indicial notation) [3 * 2]
24 //
25 // (J1,J2,J3) is given by the cross product of the columns of dxdX_{i,j}
26 //
27 // detJb is the magnitude of (J1,J2,J3)
28 //
29 // Computed:
30 //   t * (w detJb)
31 //
32 // -----------------------------------------------------------------------------
33 CEED_QFUNCTION(SetupTractionBCs)(void *ctx, CeedInt Q, const CeedScalar *const *in, CeedScalar *const *out) {
34   // Inputs
35   const CeedScalar(*J)[3][CEED_Q_VLA] = (const CeedScalar(*)[3][CEED_Q_VLA])in[0], (*w) = in[1];
36   // Outputs
37   CeedScalar(*v)[CEED_Q_VLA] = (CeedScalar(*)[CEED_Q_VLA])out[0];
38 
39   // User stress tensor
40   const CeedScalar(*traction) = (const CeedScalar(*))ctx;
41 
42   CeedPragmaSIMD
43       // Quadrature Point Loop
44       for (CeedInt i = 0; i < Q; i++) {
45     // Setup
46     const CeedScalar dxdX[3][2] = {
47         {J[0][0][i], J[1][0][i]},
48         {J[0][1][i], J[1][1][i]},
49         {J[0][2][i], J[1][2][i]}
50     };
51     // J1, J2, and J3 are given by the cross product of the columns of dxdX
52     const CeedScalar J1 = dxdX[1][0] * dxdX[2][1] - dxdX[2][0] * dxdX[1][1];
53     const CeedScalar J2 = dxdX[2][0] * dxdX[0][1] - dxdX[0][0] * dxdX[2][1];
54     const CeedScalar J3 = dxdX[0][0] * dxdX[1][1] - dxdX[1][0] * dxdX[0][1];
55 
56     // Qdata
57     // -- Interp-to-Interp q_data
58     CeedScalar wdetJb = w[i] * sqrt(J1 * J1 + J2 * J2 + J3 * J3);
59 
60     // Traction surface integral
61     for (CeedInt j = 0; j < 3; j++) v[j][i] = traction[j] * wdetJb;
62 
63   }  // End of Quadrature Point Loop
64 
65   // Return
66   return 0;
67 }
68 // -----------------------------------------------------------------------------
69 
70 #endif  // End of TRACTION_BOUNDARY_H
71