unexpected MAPDL server disconnection while running a series of aplot()

[hawkoli1987]

Dear All,

I am trying to generating a random range of 2D shapes in series, there are 100 numbers of such shapes in total. For each shape generated, I ordered a printout of it via mapdl.aplot(). After a bunch of such shapes were successfully generated, there is always an automatic server disconnection which stops me from generating new shapes.

However, if I simply change the aplot() to lplot(), it will complete the generation process successfully.

Another issue I had was that on one side of the shape, it's a curve that was generated by fitting a spline through a series of keypoints. Among all the area plots, I can always spot a few that looks like straight line-segments rather than a spline.

I would assume both issues are connected? and perhaps both was caused by insufficient memory? I attached my code here in a zip. Please enlighten me on this, thanks!

---------------------------------------------------------------------------
MapdlExitedError                          Traceback (most recent call last)
Input In [5], in <cell line: 124>()
    125 geo = Geometry(curve = line.tolist())
    126 mat = Material()
--> 127 get_Ue(mat, geo)

Input In [5], in get_Ue(mat, geo, c_r, force, disp, AESIZE, refine_lvl, detach_step)
    114 else:
    115     mapdl.rectng(0, geo.diameter/2, 0, geo.height)
--> 116 mapdl.aplot('ALL',cpos="xy")
    117 return

File ~\anaconda3\envs\pyansys_env\lib\site-packages\ansys\mapdl\core\mapdl.py:1478, in _MapdlCore.aplot(self, na1, na2, ninc, degen, scale, vtk, quality, show_area_numbering, show_line_numbering, color_areas, show_lines, **kwargs)
   1476 if quality < 1:
   1477     quality = 1
-> 1478 surf = self.geometry.generate_surface(11 - quality, na1, na2, ninc)
   1479 meshes = []
   1480 labels = []

File ~\anaconda3\envs\pyansys_env\lib\site-packages\ansys\mapdl\core\misc.py:324, in supress_logging.<locals>.wrapper(*args, **kwargs)
    321 if prior_log_level != "CRITICAL":
    322     mapdl._set_log_level("CRITICAL")
--> 324 out = func(*args, **kwargs)
    326 if prior_log_level != "CRITICAL":
    327     mapdl._set_log_level(prior_log_level)

File ~\anaconda3\envs\pyansys_env\lib\site-packages\ansys\mapdl\core\misc.py:346, in run_as_prep7.<locals>.wrapper(*args, **kwargs)
    343 if prior_processor != "PREP7":
    344     mapdl.prep7()
--> 346 out = func(*args, **kwargs)
    348 if prior_processor == "Begin level":
    349     mapdl.finish()

File ~\anaconda3\envs\pyansys_env\lib\site-packages\ansys\mapdl\core\mapdl_geometry.py:293, in Geometry.generate_surface(self, density, amin, amax, ninc)
    290     self._mapdl.prep7(mute=True)
    292 # Mesh and get the number of elements per area
--> 293 resp = self._mapdl.amesh("all")
    294 groups = get_elements_per_area(resp)
    296 self._mapdl.esla("S")

File ~\anaconda3\envs\pyansys_env\lib\site-packages\ansys\mapdl\core\_commands\preproc\meshing.py:182, in Meshing.amesh(self, na1, na2, ninc, **kwargs)
    160 """Generates nodes and area elements within areas.
    161 
    162 APDL Command: AMESH
   (...)
    179 This command is also valid for rezoning.
    180 """
    181 command = f"AMESH,{na1},{na2},{ninc}"
--> 182 return self.run(command, **kwargs)

File ~\anaconda3\envs\pyansys_env\lib\site-packages\ansys\mapdl\core\mapdl.py:2630, in _MapdlCore.run(self, command, write_to_log, mute, **kwargs)
   2627         self._check_parameter_name(param_name)
   2629 verbose = kwargs.get("verbose", False)
-> 2630 text = self._run(command, verbose=verbose, mute=mute)
   2632 if mute:
   2633     return

File ~\anaconda3\envs\pyansys_env\lib\site-packages\ansys\mapdl\core\mapdl_grpc.py:736, in MapdlGrpc._run(self, cmd, verbose, mute)
    734     response = self._send_command_stream(cmd, True)
    735 else:
--> 736     response = self._send_command(cmd, mute=mute)
    737 self._busy = False
    739 return response.strip()


File ~\anaconda3\envs\pyansys_env\lib\site-packages\ansys\mapdl\core\errors.py:138, in protect_grpc.<locals>.wrapper(*args, **kwargs)
    136     # Must close unfinished processes
    137     mapdl._close_process()
--> 138     raise MapdlExitedError("MAPDL server connection terminated") from None
    140 if threading.current_thread().__class__.__name__ == "_MainThread":
    141     received_interrupt = bool(SIGINT_TRACKER)

MapdlExitedError: MAPDL server connection terminated
---------------------------------------------------------------------------

File:

Issue.zip
hawkoli1987

[hawkoli1987]

Dear all,

Just wish to add on to this. In the last few days I realized that the "MAPDL server connection terminated" error could also come from different places in my code.

My updated code runs an iteration which creates a new geometry each time and runs a similar simulation to get the elastic energy of the entire geometry. Given the geometries are generated by a random function, there are cases when an awkward shape is generated, resulting in a plotting or meshing error. There are also cases when a curvature might be too sharp, causing an excessive local deformation and convergence failure. In both cases, I managed to handle exception via try/except statement.

However, there are cases when I even have "MAPDL server connection terminated" error resulted from the first mapdl command mapdl.clear(). In such cases, even if I use try/except statement, the iterations will continue, but the result of subsequent iterations will always be empty, it's clear that mapdl server has stopped responding.

---

F_ad_0 = 26.87
F_ad_1 = 33.93
F_ad_2 = 33.45
F_ad_3 = 75.52
F_ad_4 = 26.96
F_ad_5 = 45.02
F_ad_6 = 154.40
F_ad_7 = 49.91
F_ad_8 = 67.08
F_ad_9 = 87.31
F_ad_10 = 35.99
F_ad_11 = 43.47
F_ad_12 = 57.26
F_ad_13 = 25.97
F_ad_14 = 42.11
F_ad_15 = 76.84
F_ad_16 = 26.10
F_ad_17 = 36.06
F_ad_18 = 41.66
F_ad_19 = 43.50
F_ad_20 = 47.36
F_ad_21 = 26.66
F_ad_22 = 56.67
F_ad_23 = 63.59
F_ad_24 = 35.63
F_ad_25 = 36.13
F_ad_26 = 26.18
F_ad_27 = 43.44
F_ad_28 = 64.43
F_ad_29 = 49.91
gen0: avg=49.3, max=154.4, best =[ 1.91828297 -3.99640071 -1.22365025 2.88984312 0.42493118 -5.20767447
0.6600201 -4.53305468 2.30980953 2.10836263 5.58621429 1.23051355
-3.82257811 -2.6280593 -0.23301657 3.10000679 2.44373174 -0.40599291
1.76512176 1.86325417]
F_ad_0 = 175.20
F_ad_1 = 42.97
F_ad_2 = 43.47
F_ad_3 = 43.14
F_ad_4 = 73.11
F_ad_5 = 57.51
F_ad_6 = 103.70
F_ad_7 = 87.31
F_ad_8 = 87.31
F_ad_9 = 49.91
F_ad_10 = 60.13
F_ad_11 = 38.30
F_ad_12 = 75.52
F_ad_13 = 154.40
F_ad_14 = 66.94
F_ad_15 = 154.40
F_ad_16 = 228.01
F_ad_17 = 148.75
F_ad_18 = 65.75
F_ad_19 = 47.36
F_ad_20 = 45.02
F_ad_21 = 64.43
F_ad_22 = 47.36
F_ad_23 = 58.74
F_ad_24 = 81.97
F_ad_25 = 42.99
F_ad_26 = 41.39
F_ad_27 = 47.36
F_ad_28 = 35.63
F_ad_29 = 51.76
gen1: avg=77.3, max=228.0, best =[ 7.73989826 1.6142196 -2.53703279 -1.69170947 2.96438858 -5.04723666
-2.97967492 -1.24297326 4.05106254 -2.65950768 1.49478494 -0.38976314
-2.5242156 -0.05927039 0.05334524 2.30299762 1.68080616 -3.29943165
-0.11449578 4.89347322]
F_ad_0 = 52.74
F_ad_1 = 154.40
warning: other errors result in empty result
F_ad_2 = 0.00
warning: clear error
F_ad_3 = 0.00
warning: clear error
F_ad_4 = 0.00
warning: clear error
F_ad_5 = 0.00

---

Looking forward to your advise, thanks!

hawkoli1987