Member/material Coordinates (topic)

Also see :

How member & material coordinates differ :

  • The concept of member and material coordinate systems are basically the same. Each coordinate system consists of three axes -- X, Y and Z axes -- which meet at the 0, 0, 0 point on the left end of the member or material.
  • One difference between member and material coordinates is that the left end of a beam, column or brace is defined by that member's location within the global coordinate system . Whereas a material's left end is defined by the first point that was located when an Add Material operation was performed.
  • The material axes for beam, column and brace main material exactly correspond to the member axes. Their 0, 0, 0 point is the same point. For a legacy miscellaneous member , this may or may not be true, depending on how the work points of the member were located.
  • For a miscellaneous member and most other custom members, member and material coordinates closely or exactly correlate. However, the left end of such a member may or may not correspond to the left end of a beam or column or brace that is parallel to that member. This is because the left end of a beam, column or brace correlates to its global coordinates , but the left end of a miscellaneous member is the location of the first work point that was located when the member was added. The left end of a legacy miscellaneous member also correlates to the member's global coordinates and is identified on its [Legacy] Miscellaneous Member Edit window and by the origin symbol ( ) that is shown when that member is hovered with the ' Members ' selection filter active.

Examples of wide flange member coordinates :

  • The illustration below shows the X, Y and Z member coordinates for a wide flange beam.
The origin point for a member's coordinate system is the member's 0, 0, 0 point. This beam's 0, 0, 0 point is located at the left end of the top flange center line.
  • The following illustration shows the member coordinates for a wide flange column or miscellaneous member. Note that the 0, 0, 0 point ( origin reference point ) on this member is not at the top flange, but at the the half-depth line (along the neutral axis of the column). When visualizing the coordinates of a column, mentally turn the column on its side so that you are facing its near side and its left end (bottom end) is to your left as shown in the illustration below.

Each member has its own coordinate system :

  • The member coordinate system is a local system of coordinates which is drawn in relation to that member.
  • This means that if you rotate that member, its coordinate system remains the same. The member's X axis is always along the length of the member from left to right. The Y axis runs perpendicular to the X axis along the left end of the member. The Z axis is perpendicular to both the X and Y axes.
  • Positive and negative directions within this coordinate system are determined with respect to the left end of the member, which includes the point that is the origin of the three axes (the 0, 0, 0 point of the local coordinate system). A force whose direction is from left to right along the X axis is assigned a positive value.
  • The left end of a member is defined by that member's location in the global coordinate system , not from the viewer's perspective (see determining a member's left end ). Be aware that it is possible to create views in Modeling that show the left end of a member on your right.

Operations that relate to member & material coordinates :

  • When a miscellaneous member or material is rotated into place, you can optionally define the rotation of the material with respect to " member " or " material " axes.
  • When you do an Add Hole operation, the hole group is, by default, oriented with respect to the axes of the material you are adding the holes to. To change this orientation, enter a number of degrees other than ' 0 ' to the " Hole Group Rotation " field.
  • When entering a " Slot rotation " for system-generated holes, ' 0 ' degrees designates that the length of the slot be parallel with the X axis of the material that the hole is on.
  • When you create a structure in Modeling from an SDS2 neutral file using Import Model , the 0, 0, 0 member coordinate of each member is positioned according to the global coordinates specified in the "FC" records of the neutral file for that member.
  • Doing a Edit Member displays the reference point on the member . This reference point is the 0, 0, 0 member coordinate.
  • Doing a Rotate Material displays the material reference point. This reference point is the 0, 0, 0 material coordinate.
  • CNC data that defines the placement of holes in a CNC download file is measured with respect to material axes.