Envelopes

This mode is used to solve a partial problem of determination of the basic unfavorable combinations of multiple loads acting on bending members.

It should be noted that the temporary loads implicitly include a zero load (it enables to describe the case of absence of all temporary loads). Therefore, when calculating maximum values (e.g., bending moments) we take the greatest of the positive moments and zero, and when calculating minimum values we take the least of the negative moments and zero.

Specify the beam span in the Envelopes dialog box and click the Apply button. Select one of the following boundary conditions using buttons on the top right: clamped at both ends; simply supported; hinged at one end and clamped at the other; or a cantilever beam.

The application is capable of analyzing several (up to ten) patterns of loading, and each load case can in its turn consist of multiple loads.

To enter a new load case (including the first one), follow these steps:

A few load components can be specified for each load case. It is assumed that the design values of loads are entered.

Depending on the load type, its parameters may include:

The Delete button is used to delete a load case (not a separate load included in it).

To switch to the next load case, click the Create button, and the number of load cases will be automatically increased by one. If you need to view or modify the data from any of the previously entered load cases, just select its number in the Loadings list.

Once you click the Add button, an image of the current loading is displayed in the Diagrams fields with the superimposed diagrams of the bending moments and shear forces underneath. Once you have entered all the loadings, you can view the values of the extreme moments and their corresponding shear forces, as well as the extreme shear forces and their corresponding bending moments. This can be done by selecting the respective item from the drop-down list above the Diagrams field. The envelope diagrams of maximal and minimal forces are displayed separately.

If you place the mouse pointer in the diagram field, values of the moment and shear force in a particular cross-section corresponding to the position of the pointer will be displayed.

Moreover, the report document will contain a table with support reactions.

To edit (and to delete, if necessary) particular loads from one load case, you can use a table of loads which is displayed in the respective dialog box after you click the button image\ebx_-864903457.jpg. In this table, you can modify the value of a load or its application point, and delete one or more loads. In the latter case select the icon of the load you want to delete and click the Delete button.