Physical member dist load fix

Author: JWock82

PyNite/PhysMember.py

@@ -117,7 +117,7 @@ def descritize(self):
                     if x2_load < xj:
                         x2 = x2_load - xi
                     else:
-                        x2 = xj
+                        x2 = xj - xi
                         w2 = w(xj)
 
                     # Add the load to the sub-member

README.md

@@ -64,6 +64,9 @@ PyNite depends on the following packages:
 
 # What's New?
 
+v0.0.68
+* Bug fix for member distributed loads on physical members. Added a unit test to check for this error going forward. This bug only affected physical members (new as of v0.0.67) that had distributed loads and internal nodes.
+
 v0.0.67
 * Added physical members. Members now automatically detect internal nodes and subdivide themselves and their loads.
 * Refactoring: deprecated old method names for member results. You may now have some errors show up if you still try to get member results using the old method names.

Testing/test_member_internal_results.py

@@ -0,0 +1,71 @@
+# -*- coding: utf-8 -*-
+"""
+MIT License
+
+Copyright (c) 2020 D. Craig Brinck, SE; tamalone1
+"""
+
+import unittest
+from PyNite import FEModel3D
+import math
+import sys
+from io import StringIO
+
+class TestMemberInternalResults(unittest.TestCase):
+    """
+    Tests for member internal results
+    """
+
+    def setUp(self):
+        # Suppress printed output temporarily
+        sys.stdout = StringIO()
+
+    def tearDown(self):
+        # Reset the print function to normal
+        sys.stdout = sys.__stdout__
+
+    def test_beam_shear(self):
+        """
+        Units for this model are kips and feet
+        """
+
+        # Define a new beam
+        beam = FEModel3D()
+
+        # Define the nodes
+        beam.add_node('N1', 0, 0, 0)
+        beam.add_node('N2', 10, 0, 0)
+
+        # Define the supports
+        beam.def_support('N1', True, True, True, True, False, False)
+        beam.def_support('N2', True, True, True, False, False, False)
+
+        # Define beam section proerties
+        J = 400/12**4
+        Iy = 200/12**4
+        Iz = 200/12**4
+        E = 29000*144
+        G = 11200*144
+        A = 12/12**2
+
+        # Create the beam
+        beam.add_member('M1', 'N1', 'N2', E, G, Iy, Iz, J, A)
+
+        # Add a mid-span node
+        beam.add_node('N3', 5, 0, 0)
+
+        # Add a member distributed load
+        beam.add_member_dist_load('M1', 'FY', -0.5, -0.5, case='D')
+        beam.add_load_combo('D', {'D':1.0})
+
+        # Analyze the model
+        beam.analyze_linear()
+
+        # from PyNite.Visualization import Renderer
+        # renderer = Renderer(beam)
+        # renderer.combo_name = 'D'
+        # renderer.annotation_size = 1
+        # renderer.render_model()
+
+        # Check the shear at midspan - it should be zero
+        self.assertAlmostEqual(beam.Members['M1'].shear('Fy', 5, 'D'), 0, 2)

setup.py

@@ -5,7 +5,7 @@
 
 setuptools.setup(
     name="PyNiteFEA",
-    version="0.0.67",
+    version="0.0.68",
     author="D. Craig Brinck, PE, SE",
     author_email="Building.Code@outlook.com",
     description="A simple elastic 3D structural finite element library for Python.",