Merge pull request #1054 from jguarato/fix-nlinks-6dof

Fix n_links for the 6 dof model

ross/bearing_seal_element.py

@@ -2128,6 +2128,12 @@ def M(self, frequency):
 
         M = np.array([[mxx, mxy, 0], [myx, myy, 0], [0, 0, mzz]])
 
+        if self.n_link is not None:
+            # fmt: off
+            M = np.vstack((np.hstack([M, -M]),
+                           np.hstack([-M, M])))
+            # fmt: on
+
         return M
 
     def K(self, frequency):
@@ -2161,6 +2167,12 @@ def K(self, frequency):
 
         K = np.array([[kxx, kxy, 0], [kyx, kyy, 0], [0, 0, kzz]])
 
+        if self.n_link is not None:
+            # fmt: off
+            K = np.vstack((np.hstack([K, -K]),
+                           np.hstack([-K, K])))
+            # fmt: on
+
         return K
 
     def C(self, frequency):
@@ -2194,6 +2206,12 @@ def C(self, frequency):
 
         C = np.array([[cxx, cxy, 0], [cyx, cyy, 0], [0, 0, czz]])
 
+        if self.n_link is not None:
+            # fmt: off
+            C = np.vstack((np.hstack([C, -C]),
+                           np.hstack([-C, C])))
+            # fmt: on
+
         return C
 
 

ross/disk_element.py

@@ -667,17 +667,17 @@ def Kdt(self):
                [0.  , 0.  , 0.  , 0.  , 0.  , 0.  ],
                [0.  , 0.  , 0.  , 0.  , 0.  , 0.  ],
                [0.  , 0.  , 0.  , 0.  , 0.  , 0.  ],
-               [0.  , 0.  , 0.  , 0.  , 0.  , 0.  ],
-               [0.  , 0.  , 0.  , 0.33, 0.  , 0.  ]])
+               [0.  , 0.  , 0.  , 0.33, 0.  , 0.  ],
+               [0.  , 0.  , 0.  , 0.  , 0.  , 0.  ]])
         """
         Ip = self.Ip
         # fmt: off
         Kdt = np.array([[0, 0, 0,  0, 0, 0],
                         [0, 0, 0,  0, 0, 0],
                         [0, 0, 0,  0, 0, 0],
                         [0, 0, 0,  0, 0, 0],
-                        [0, 0, 0,  0, 0, 0],
-                        [0, 0, 0, Ip, 0, 0]])
+                        [0, 0, 0, Ip, 0, 0],
+                        [0, 0, 0,  0, 0, 0]])
         # fmt: on
         return Kdt
 

ross/point_mass.py

@@ -13,7 +13,7 @@
 from ross.element import Element
 from ross.units import check_units
 
-__all__ = ["PointMass"]
+__all__ = ["PointMass", "PointMass6DoF"]
 
 
 class PointMass(Element):
@@ -66,6 +66,7 @@ def __init__(self, n=None, m=None, mx=None, my=None, tag=None, color="DarkSalmon
         self.tag = tag
         self.dof_global_index = None
         self.color = color
+        self.size = 2
 
     def __hash__(self):
         return hash(self.tag)
@@ -180,7 +181,7 @@ def C(self):
         array([[0., 0.],
                [0., 0.]])
         """
-        C = np.zeros((2, 2))
+        C = np.zeros((self.size, self.size))
         return C
 
     def K(self):
@@ -201,7 +202,7 @@ def K(self):
         array([[0., 0.],
                [0., 0.]])
         """
-        K = np.zeros((2, 2))
+        K = np.zeros((self.size, self.size))
         return K
 
     def G(self):
@@ -222,7 +223,7 @@ def G(self):
         array([[0., 0.],
                [0., 0.]])
         """
-        G = np.zeros((2, 2))
+        G = np.zeros((self.size, self.size))
         return G
 
     def dof_mapping(self):
@@ -324,6 +325,240 @@ def _patch(self, position, fig):
         return fig
 
 
+class PointMass6DoF(PointMass):
+    """A point mass element.
+
+    This class will create a point mass element.
+    This element can be used to link other elements in the analysis.
+    The mass provided to the element can be different on the x, y and z directions
+    (e.g. different support inertia for x, y and z directions).
+
+    Parameters
+    ----------
+    n: int
+        Node which the bearing will be located in.
+    m: float, pint.Quantity, optional
+        Mass for the element.
+    mx: float, pint.Quantity, optional
+        Mass for the element on the x direction.
+    my: float, pint.Quantity, optional
+        Mass for the element on the y direction.
+    mz: float, pint.Quantity, optional
+        Mass for the element on the z direction.
+    tag: str
+        A tag to name the element
+    color : str, optional
+        A color to be used when the element is represented.
+        Default is "DarkSalmon".
+
+    Examples
+    --------
+    >>> p0 = PointMass6DoF(n=0, m=2)
+    >>> p0.M()
+    array([[2., 0., 0.],
+           [0., 2., 0.],
+           [0., 0., 2.]])
+    >>> p1 = PointMass6DoF(n=0, mx=2, my=3, mz=4)
+    >>> p1.M()
+    array([[2., 0., 0.],
+           [0., 3., 0.],
+           [0., 0., 4.]])
+    """
+
+    @check_units
+    def __init__(
+        self, n=None, m=None, mx=None, my=None, mz=None, tag=None, color="DarkSalmon"
+    ):
+        self.n = n
+
+        if mx is None and my is None:
+            mx = float(m)
+            my = float(m)
+            mz = float(m)
+
+        self.mx = float(mx)
+        self.my = float(my)
+        self.mz = float(mz)
+        self.tag = tag
+        self.dof_global_index = None
+        self.color = color
+        self.size = 3
+
+    def __repr__(self):
+        """Return a string representation of a point mass element.
+
+        Returns
+        -------
+        A string representation of a point mass element object.
+
+        Examples
+        --------
+        >>> point_mass = point_mass_example_6dof()
+        >>> point_mass
+        PointMass6DoF(n=0, mx=1.0, my=2.0, mz=3.0, tag='pointmass')
+        """
+        return (
+            f"{self.__class__.__name__}"
+            f"(n={self.n}, mx={self.mx:{0}.{5}},"
+            f" my={self.my:{0}.{5}},"
+            f" mz={self.mz:{0}.{5}},"
+            f" tag={self.tag!r})"
+        )
+
+    def __str__(self):
+        """Convert object into string.
+
+        Returns
+        -------
+        The object's parameters translated to strings
+
+        Example
+        -------
+        >>> print(PointMass6DoF(n=0, mx=2.5, my=3.25, mz=4.15, tag="PointMass"))
+        Tag:              PointMass
+        Node:             0
+        Mass X dir. (kg): 2.5
+        Mass Y dir. (kg): 3.25
+        Mass Z dir. (kg): 4.15
+        """
+        return (
+            f"Tag:              {self.tag}"
+            f"\nNode:             {self.n}"
+            f"\nMass X dir. (kg): {self.mx:{2}.{5}}"
+            f"\nMass Y dir. (kg): {self.my:{2}.{5}}"
+            f"\nMass Z dir. (kg): {self.mz:{2}.{5}}"
+        )
+
+    def M(self):
+        """Mass matrix for an instance of a point mass element.
+
+        This method will return the mass matrix for an instance of a point mass element.
+
+        Returns
+        -------
+        M : np.ndarray
+            A matrix of floats containing the values of the mass matrix.
+
+        Examples
+        --------
+        >>> p1 = PointMass6DoF(n=0, mx=2, my=3, mz=4)
+        >>> p1.M()
+        array([[2., 0., 0.],
+               [0., 3., 0.],
+               [0., 0., 4.]])
+        """
+        mx = self.mx
+        my = self.my
+        mz = self.mz
+        # fmt: off
+        M = np.array([[mx,  0,  0],
+                      [ 0, my,  0],
+                      [ 0,  0, mz]])
+        # fmt: on
+
+        return M
+
+    def dof_mapping(self):
+        """Degrees of freedom mapping.
+
+        Returns a dictionary with a mapping between degree of freedom and its index.
+
+        Returns
+        -------
+        dof_mapping : dict
+            A dictionary containing the degrees of freedom and their indexes.
+
+        Examples
+        --------
+        The numbering of the degrees of freedom for each node.
+
+        Being the following their ordering for a node:
+
+        x_0 - horizontal translation
+        y_0 - vertical translation
+        z_0 - axial translation
+
+        >>> p1 = PointMass6DoF(n=0, mx=2, my=3, mz=4)
+        >>> p1.dof_mapping()
+        {'x_0': 0, 'y_0': 1, 'z_0': 2}
+        """
+        return dict(x_0=0, y_0=1, z_0=2)
+
+    def _patch(self, position, fig):
+        """Point mass element patch.
+
+        Patch that will be used to draw the point mass element using Plotly library.
+
+        Parameters
+        ----------
+        position : float
+            Position in which the patch will be drawn.
+        fig : plotly.graph_objects.Figure
+            The figure object which traces are added on.
+
+        Returns
+        -------
+        fig : plotly.graph_objects.Figure
+            The figure object which traces are added on.
+        """
+        zpos, ypos = position
+        radius = ypos / 12
+
+        customdata = [self.n, self.mx, self.my, self.mz]
+        hovertemplate = (
+            f"PointMass Node: {customdata[0]}<br>"
+            + f"Mass (X): {customdata[1]:.3f}<br>"
+            + f"Mass (Y): {customdata[2]:.3f}<br>"
+            + f"Mass (Z): {customdata[2]:.3f}<br>"
+        )
+
+        fig.add_trace(
+            go.Scatter(
+                x=[zpos, zpos],
+                y=[ypos, -ypos],
+                customdata=[customdata] * 2,
+                text=hovertemplate,
+                mode="markers",
+                marker=dict(size=5.0, color=self.color),
+                showlegend=False,
+                name=self.tag,
+                legendgroup="pointmass",
+                hoverinfo="text",
+                hovertemplate=hovertemplate,
+                hoverlabel=dict(bgcolor=self.color),
+            )
+        )
+
+        fig.add_shape(
+            dict(
+                type="circle",
+                xref="x",
+                yref="y",
+                x0=zpos - radius,
+                y0=ypos - radius,
+                x1=zpos + radius,
+                y1=ypos + radius,
+                fillcolor=self.color,
+                line_color="black",
+            )
+        )
+        fig.add_shape(
+            dict(
+                type="circle",
+                xref="x",
+                yref="y",
+                x0=zpos - radius,
+                y0=-ypos - radius,
+                x1=zpos + radius,
+                y1=-ypos + radius,
+                fillcolor=self.color,
+                line_color="black",
+            )
+        )
+
+        return fig
+
+
 def point_mass_example():
     """Create an example of point mass element.
 
@@ -346,3 +581,28 @@ def point_mass_example():
     my = 2.0
     point_mass = PointMass(n=n, mx=mx, my=my, tag="pointmass")
     return point_mass
+
+
+def point_mass_example_6dof():
+    """Create an example of point mass element for the 6 dof model.
+
+    This function returns an instance of a simple point mass. The purpose is to make
+    available a simple model so that doctest can be written using it.
+
+    Returns
+    -------
+    point_mass : ross.PointMass
+        An instance of a point mass object.
+
+    Examples
+    --------
+    >>> pointmass = point_mass_example_6dof()
+    >>> pointmass.mz
+    3.0
+    """
+    n = 0
+    mx = 1.0
+    my = 2.0
+    mz = 3.0
+    point_mass = PointMass6DoF(n=n, mx=mx, my=my, mz=mz, tag="pointmass")
+    return point_mass