Point Springs

Form: Point Spring Properties, Point Spring Property Data

Use the Define menu > Spring Properties > Point Springs command to access the Point Spring Properties form and add, modify, or delete a point spring property definition that can be assigned to a point object. Point spring property definitions are used to specify the spring stiffness values in each of the translational and rotational directions.

Note: The point spring properties also can be accessed by right clicking the Spring Properties sub node, or right clicking on one of the items in the list under this sub node, both under the Properties node on the Model tab in the Model Explorer window. Additionally, the Point Spring Properties form also displays when the Modify/Show Definitions button is clicked on the Joint Assignments - Springs form.

• Add New Property button. Click this button to access the Point Spring Property Data form, and define the new spring definition:

• • General Data: Input the name of the spring property in the edit box, set the display color and click the Modify/Show Notes button to add spring property notes.

  • Spring Stiffness Options: Select either the User Specified/Link Properties option or the Based on Soil Profile and Footing Dimensions option to determine how the point spring should be defined.

  • User Specified/Link Properties:

  • Simple Spring Stiffness in Global Directions: Input spring stiffness values in each of the three global translational and three rotational directions.

  • Single Joint Links at Point options. In addition to any Simple Spring Stiffness, one or more single-joint (grounded) link properties may be added to the joint to specify the support conditions. For each link property to be specified, click the Add button. This will add a data row that can be used to specify a previously defined link property, the axial (local 1 axis) direction, and the local 2 axis angle. In most cases either Simple Spring Stiffness or a single link property would be used. However, multiple properties may be needed for advanced purposes.

  • Based on Soil Profile and Footing Dimensions: Available only if at least one soil profile and one isolated column footing have previously been defined. Selecting this option means that foundation springs and dashpots will be generated automatically by the program for soil-foundation interaction at column bases where this point spring is assigned .

  • Soil Profile. Select a previously defined soil profile from the drop-down list.

  • Isolated Column Footing. Select a previously defined isolated column footing from the drop-down list.

  • First-Mode Time Period. Enter the time period for the fundamental mode of the building structure.

Click the OK button to complete the spring property data definition.

• Add Copy of Property button.

• 1. Highlight one of the spring properties in the Point Spring Property list and click this button to access the Point Spring Property Data form.

  2. All edit boxes, drop-down lists, and option selections (except for the Property Name) on that form will be populated with values identical to those of the highlighted spring property. Values may be revised as necessary and then saved to create a new point spring property definition.

• Modify/Show Property button.

• 1.  Highlight one of the spring properties in the Point Spring Property list and click this button to access the property specific Point Spring Property Data form, which displays the various values that comprise the property definition.

  2. Review and revise the data as necessary.

• Delete Property button.

• 1. Highlight one of the spring properties in the Point Spring Property list.

  2. Click this button to remove this property from the model.

Note: "None" is included in the Springs list  on the Joint Assignment - Springs form when using the Assign menu > Joint > Springs command. When None is highlighted, only the Add New Property button is available because the "None definition" is empty and has no values associated with it. Selecting the None property definition and assigning it to an object removes any definition previously assigned to that object.

TIP: The  Calculator feature can be used to assist with mathematical operations during data entry Place the mouse pointer/cursor in an edit box, hold down the Shift key and double click the left mouse button to access the form.