Working with Analyses

There are two ways to create an Analysis Window: create a new analysis with the Analysis Wizard or open an existing analysis (cfsa) file. The analysis window contains a graphic of the members, supports, and loads. Simple beams, continuous beams, beams with laps, and beam-columns are examples of the types of problems that can be analyzed.

All the inputs for an analysis are contained in the Analysis Inputs window. These inputs are grouped into five categories, each on a separate page in the window. The General Page contains inputs and information for the analysis. The Members Page contains inputs that define the members in the analysis. The Supports Page contains inputs that define the member supports. The Loadings Page contains inputs that define loads applied to the members, and are grouped into different loadings. The Combinations Page contains inputs that define combinations of loadings to analyze.

All geometric locations are input using a one-dimensional global coordinate system. Members, supports, and loads are all defined independently, so that members may span across multiple supports, and loads may span across multiple members. Node numbers and beam elements are assigned internally by CFS and are invisible to the user. The plot of the geometry may be shown in either a horizontal or vertical orientation.

Each member has an associated section, and all sections used in an analysis must be open (loaded) when working with the analysis. The orientation of the section is as viewed from the left end (or top end) of the member. Lapped members are assumed to provide full continuity.

Supports may be horizontal (X), vertical (Y), torsional (T), and rotational about both X and Y axes (Rx and Ry). CFS does not consider ends of overlapped sections as support locations. If you want to consider these as support points, you must explicitly define them.

Loads are grouped by loading type (dead, live, etc.), and numerous ASD and LRFD load combinations may be defined. Transverse loads may be distributed (uniform or trapezoidal) as well as concentrated, and may be in any direction perpendicular to the members. Axial loads are defined by specifying both ends: the point of application and the point of restraint.

Once an analysis is defined, computations may be performed for one load combination at a time. The current combination on the Combinations Page of the Analysis Inputs is displayed in the analysis window. You may create shear, moment, and deflection diagrams, and you may also compute member checks and web crippling checks for any location. These are accessed from the Compute menu.