int main(int argc, char* argv[]) {
// Create output directories.
if (ChFileutils::MakeDirectory(out_dir.c_str()) < 0) {
cout << "Error creating directory " << out_dir << endl;
return 1;
}
if (ChFileutils::MakeDirectory(pov_dir.c_str()) < 0) {
cout << "Error creating directory " << pov_dir << endl;
return 1;
}
// -------------
// Create system
// -------------
#ifdef USE_DEM
cout << "Create DEM system" << endl;
ChSystemParallelDEM* msystem = new ChSystemParallelDEM();
#else
cout << "Create DVI system" << endl;
ChSystemParallelDVI* msystem = new ChSystemParallelDVI();
#endif
msystem->Set_G_acc(ChVector<>(0, 0, -gravity));
// Set number of threads.
int max_threads = omp_get_num_procs();
if (threads > max_threads)
threads = max_threads;
msystem->SetParallelThreadNumber(threads);
omp_set_num_threads(threads);
cout << "Using " << threads << " threads" << endl;
msystem->GetSettings()->max_threads = threads;
msystem->GetSettings()->perform_thread_tuning = thread_tuning;
// Edit system settings
msystem->GetSettings()->solver.use_full_inertia_tensor = false;
msystem->GetSettings()->solver.tolerance = tolerance;
msystem->GetSettings()->solver.max_iteration_bilateral = max_iteration_bilateral;
msystem->GetSettings()->solver.clamp_bilaterals = clamp_bilaterals;
msystem->GetSettings()->solver.bilateral_clamp_speed = bilateral_clamp_speed;
#ifdef USE_DEM
msystem->GetSettings()->collision.narrowphase_algorithm = NARROWPHASE_R;
msystem->GetSettings()->solver.contact_force_model = contact_force_model;
msystem->GetSettings()->solver.tangential_displ_mode = tangential_displ_mode;
#else
msystem->GetSettings()->solver.solver_mode = SLIDING;
msystem->GetSettings()->solver.max_iteration_normal = max_iteration_normal;
msystem->GetSettings()->solver.max_iteration_sliding = max_iteration_sliding;
msystem->GetSettings()->solver.max_iteration_spinning = max_iteration_spinning;
msystem->GetSettings()->solver.alpha = 0;
msystem->GetSettings()->solver.contact_recovery_speed = contact_recovery_speed;
msystem->SetMaxPenetrationRecoverySpeed(contact_recovery_speed);
msystem->ChangeSolverType(APGDREF);
msystem->GetSettings()->collision.collision_envelope = 0.05 * r_g;
#endif
msystem->GetSettings()->collision.bins_per_axis = I3(10, 10, 10);
// --------------
// Problem set up
// --------------
// Depending on problem type:
// - Select end simulation time
// - Select output FPS
// - Create / load objects
double time_min = 0;
double time_end;
int out_fps;
ChSharedPtr<ChBody> ground;
ChSharedPtr<ChBody> loadPlate;
ChSharedPtr<ChLinkLockPrismatic> prismatic;
ChSharedPtr<ChLinkLinActuator> actuator;
switch (problem) {
case SETTLING: {
time_min = time_settling_min;
time_end = time_settling_max;
out_fps = out_fps_settling;
// Create the mechanism bodies (all fixed).
CreateMechanismBodies(msystem);
// Grab handles to mechanism bodies (must increase ref counts)
ground = ChSharedPtr<ChBody>(msystem->Get_bodylist()->at(0));
loadPlate = ChSharedPtr<ChBody>(msystem->Get_bodylist()->at(1));
msystem->Get_bodylist()->at(0)->AddRef();
msystem->Get_bodylist()->at(1)->AddRef();
// Create granular material.
int num_particles = CreateGranularMaterial(msystem);
cout << "Granular material: " << num_particles << " particles" << endl;
break;
}
case PRESSING: {
time_min = time_pressing_min;
time_end = time_pressing_max;
out_fps = out_fps_pressing;
// Create bodies from checkpoint file.
cout << "Read checkpoint data from " << settled_ckpnt_file;
utils::ReadCheckpoint(msystem, settled_ckpnt_file);
cout << " done. Read " << msystem->Get_bodylist()->size() << " bodies." << endl;
// Grab handles to mechanism bodies (must increase ref counts)
ground = ChSharedPtr<ChBody>(msystem->Get_bodylist()->at(0));
loadPlate = ChSharedPtr<ChBody>(msystem->Get_bodylist()->at(1));
msystem->Get_bodylist()->at(0)->AddRef();
msystem->Get_bodylist()->at(1)->AddRef();
// Move the load plate just above the granular material.
double highest, lowest;
FindHeightRange(msystem, lowest, highest);
ChVector<> pos = loadPlate->GetPos();
double z_new = highest + 1.01 * r_g;
loadPlate->SetPos(ChVector<>(pos.x, pos.y, z_new));
// Add collision geometry to plate
loadPlate->GetCollisionModel()->ClearModel();
utils::AddBoxGeometry(loadPlate.get_ptr(), ChVector<>(hdimX_p, hdimY_p, hdimZ_p), ChVector<>(0, 0, hdimZ_p));
loadPlate->GetCollisionModel()->BuildModel();
// If using an actuator, connect the load plate and get a handle to the actuator.
if (use_actuator) {
ConnectLoadPlate(msystem, ground, loadPlate);
prismatic = msystem->SearchLink("prismatic").StaticCastTo<ChLinkLockPrismatic>();
actuator = msystem->SearchLink("actuator").StaticCastTo<ChLinkLinActuator>();
}
// Release the load plate.
loadPlate->SetBodyFixed(!use_actuator);
break;
}
case TESTING: {
time_end = time_testing;
out_fps = out_fps_testing;
// For TESTING only, increse shearing velocity.
desiredVelocity = 0.5;
// Create the mechanism bodies (all fixed).
CreateMechanismBodies(msystem);
// Create the test ball.
CreateBall(msystem);
// Grab handles to mechanism bodies (must increase ref counts)
ground = ChSharedPtr<ChBody>(msystem->Get_bodylist()->at(0));
loadPlate = ChSharedPtr<ChBody>(msystem->Get_bodylist()->at(1));
msystem->Get_bodylist()->at(0)->AddRef();
msystem->Get_bodylist()->at(1)->AddRef();
// Move the load plate just above the test ball.
ChVector<> pos = loadPlate->GetPos();
double z_new = 2.1 * radius_ball;
loadPlate->SetPos(ChVector<>(pos.x, pos.y, z_new));
// Add collision geometry to plate
loadPlate->GetCollisionModel()->ClearModel();
utils::AddBoxGeometry(loadPlate.get_ptr(), ChVector<>(hdimX_p, hdimY_p, hdimZ_p), ChVector<>(0, 0, hdimZ_p));
loadPlate->GetCollisionModel()->BuildModel();
// If using an actuator, connect the shear box and get a handle to the actuator.
if (use_actuator) {
ConnectLoadPlate(msystem, ground, loadPlate);
actuator = msystem->SearchLink("actuator").StaticCastTo<ChLinkLinActuator>();
}
// Release the shear box when using an actuator.
loadPlate->SetBodyFixed(!use_actuator);
break;
}
}
// ----------------------
// Perform the simulation
// ----------------------
// Set number of simulation steps and steps between successive output
int num_steps = (int)std::ceil(time_end / time_step);
int out_steps = (int)std::ceil((1.0 / time_step) / out_fps);
int write_steps = (int)std::ceil((1.0 / time_step) / write_fps);
// Initialize counters
double time = 0;
int sim_frame = 0;
int out_frame = 0;
int next_out_frame = 0;
double exec_time = 0;
int num_contacts = 0;
double max_cnstr_viol[2] = {0, 0};
// Circular buffer with highest particle location
// (only used for SETTLING or PRESSING)
int buffer_size = std::ceil(time_min / time_step);
std::valarray<double> hdata(0.0, buffer_size);
// Create output files
ChStreamOutAsciiFile statsStream(stats_file.c_str());
ChStreamOutAsciiFile sinkageStream(sinkage_file.c_str());
sinkageStream.SetNumFormat("%16.4e");
#ifdef CHRONO_PARALLEL_HAS_OPENGL
opengl::ChOpenGLWindow& gl_window = opengl::ChOpenGLWindow::getInstance();
gl_window.Initialize(1280, 720, "Pressure Sinkage Test", msystem);
gl_window.SetCamera(ChVector<>(0, -10 * hdimY, hdimZ), ChVector<>(0, 0, hdimZ), ChVector<>(0, 0, 1));
gl_window.SetRenderMode(opengl::WIREFRAME);
#endif
// Loop until reaching the end time...
while (time < time_end) {
// Current position and velocity of the shear box
ChVector<> pos_old = loadPlate->GetPos();
ChVector<> vel_old = loadPlate->GetPos_dt();
// Calculate minimum and maximum particle heights
double highest, lowest;
FindHeightRange(msystem, lowest, highest);
// If at an output frame, write PovRay file and print info
if (sim_frame == next_out_frame) {
cout << "------------ Output frame: " << out_frame + 1 << endl;
cout << " Sim frame: " << sim_frame << endl;
cout << " Time: " << time << endl;
cout << " Load plate pos: " << pos_old.z << endl;
cout << " Lowest point: " << lowest << endl;
cout << " Highest point: " << highest << endl;
cout << " Execution time: " << exec_time << endl;
// Save PovRay post-processing data.
if (write_povray_data) {
char filename[100];
sprintf(filename, "%s/data_%03d.dat", pov_dir.c_str(), out_frame + 1);
utils::WriteShapesPovray(msystem, filename, false);
}
// Create a checkpoint from the current state.
if (problem == SETTLING || problem == PRESSING) {
cout << " Write checkpoint data " << flush;
if (problem == SETTLING)
utils::WriteCheckpoint(msystem, settled_ckpnt_file);
else
utils::WriteCheckpoint(msystem, pressed_ckpnt_file);
cout << msystem->Get_bodylist()->size() << " bodies" << endl;
}
// Increment counters
out_frame++;
next_out_frame += out_steps;
}
// Check for early termination of a settling phase.
if (problem == SETTLING) {
// Store maximum particle height in circular buffer
hdata[sim_frame % buffer_size] = highest;
// Check variance of data in circular buffer
if (time > time_min) {
double mean_height = hdata.sum() / buffer_size;
std::valarray<double> x = hdata - mean_height;
double var = std::sqrt((x * x).sum() / buffer_size);
// Consider the material settled when the variance is below the
// specified fraction of a particle radius
if (var < settling_tol * r_g) {
cout << "Granular material settled... time = " << time << endl;
break;
}
}
}
// Advance simulation by one step
#ifdef CHRONO_PARALLEL_HAS_OPENGL
if (gl_window.Active()) {
gl_window.DoStepDynamics(time_step);
gl_window.Render();
} else
break;
#else
msystem->DoStepDynamics(time_step);
#endif
TimingOutput(msystem);
// Record stats about the simulation
if (sim_frame % write_steps == 0) {
// write stat info
int numIters = msystem->data_manager->measures.solver.maxd_hist.size();
double residual = 0;
if (numIters)
residual = msystem->data_manager->measures.solver.residual;
statsStream << time << ", " << exec_time << ", " << num_contacts / write_steps << ", " << numIters << ", "
<< residual << ", " << max_cnstr_viol[0] << ", " << max_cnstr_viol[1] << ", \n";
statsStream.GetFstream().flush();
num_contacts = 0;
max_cnstr_viol[0] = 0;
max_cnstr_viol[1] = 0;
}
if (problem == PRESSING || problem == TESTING) {
// Get the current reaction force or impose load plate position
double cnstr_force = 0;
if (use_actuator) {
cnstr_force = actuator->Get_react_force().x;
} else {
double zpos_new = pos_old.z + desiredVelocity * time_step;
loadPlate->SetPos(ChVector<>(pos_old.x, pos_old.y, zpos_new));
loadPlate->SetPos_dt(ChVector<>(0, 0, desiredVelocity));
}
if (sim_frame % write_steps == 0) {
// std::cout << time << ", " << loadPlate->GetPos().z << ", " << cnstr_force << ", \n";
sinkageStream << time << ", " << loadPlate->GetPos().z << ", " << cnstr_force << ", \n";
sinkageStream.GetFstream().flush();
}
}
// Find maximum constraint violation
if (!prismatic.IsNull()) {
ChMatrix<>* C = prismatic->GetC();
for (int i = 0; i < 5; i++)
max_cnstr_viol[0] = std::max(max_cnstr_viol[0], std::abs(C->GetElement(i, 0)));
}
if (!actuator.IsNull()) {
ChMatrix<>* C = actuator->GetC();
max_cnstr_viol[1] = std::max(max_cnstr_viol[2], std::abs(C->GetElement(0, 0)));
}
// Increment counters
time += time_step;
sim_frame++;
exec_time += msystem->GetTimerStep();
num_contacts += msystem->GetNcontacts();
// If requested, output detailed timing information for this step
if (sim_frame == timing_frame)
msystem->PrintStepStats();
}
// ----------------
// Final processing
// ----------------
// Create a checkpoint from the last state
if (problem == SETTLING || problem == PRESSING) {
cout << " Write checkpoint data " << flush;
if (problem == SETTLING)
utils::WriteCheckpoint(msystem, settled_ckpnt_file);
else
utils::WriteCheckpoint(msystem, pressed_ckpnt_file);
cout << msystem->Get_bodylist()->size() << " bodies" << endl;
}
// Final stats
cout << "==================================" << endl;
cout << "Number of bodies: " << msystem->Get_bodylist()->size() << endl;
cout << "Simulation time: " << exec_time << endl;
cout << "Number of threads: " << threads << endl;
return 0;
}
