ASDIP CONCRETE is a structural engineering software for design of concrete members. It includes the design of continuous beams based on the latest ACI 318 provisions. A new feature has been implemented to design beams for torsion.
But how do you enter the information in the program? How do you check the results? How do you optimize the design? How do you print out the reports? The following is an overview of the user-interface and the steps required to design concrete beams for torsion using ASDIP CONCRETE.
Specify the beam geometry
ASDIP CONCRETE supports five types of beams according to the shape of the cross section. In the Geometry tab select the beam type and enter the dimensions of the section. Up to 5 spans and two end overhangs can be modeled in ASDIP CONCRETE.
ASDIP CONCRETE shows a summary of the results in the At-a-Glance tab for a quick overview of the concrete beam design as you go. The screen shot below shows the Geometry tab and the At-a-Glance tab. Note that in this page any problem can be identified immediately.
Specify the material properties
In the Materials tab enter the material properties. ASDIP CONCRETE lets you specify the concrete stress-strain distribution as either the parabolic Hognestad's curve, or the simplified equivalent Whitney's rectangular block. Likewise, ASDIP CONCRETE lets you specify the steel stress-strain distribution as either the Elasto-plastic bi-linear relationship, or considering the Strain-hardening zone.
ASDIP CONCRETE generates a condensed presentation of the results, with a more detailed information organized by topic and load combination, for a quick granular check of the beam design as you go. The screen shot below shows the Materials tab and the Condensed tab. Note the section for torsion design.
Enter the applied loads
Use the Loads tab to enter the applied loads on the beam. ASDIP CONCRETE lets you specify axial loads and bending moments at top and bottom. Loads can be specified either a set of load cases, such as dead, live, roof live, snow, wind, and seismic, to be combined per the specified load combinations, or a set of pre-combined loads.
In both scenarios, the loads can be entered as uniform, variable, concentrated, and moment loads. To design beams for torsion, enter the eccentricity perpendicular to the axis of the beam, and select the loads that are affected by this eccentricity. To do so, check the corresponding Torsion box as shown below. In addition, if the torsional moments can be redistributed, check the box "Torsion may be reduced" and the program will use the minimum of Tu and φTcr for torsion design.
ASDIP CONCRETE generates a detailed presentation of the results, showing step-by-step calculations organized by topic and load combination, with exposed formulas and references to the ACI code. This is excellent for a deep granular check of the design. The screen shot below shows the Loads tab and the Detailed tab. Note the design calculations of the beam for torsion.
Designing Beams for Torsion
The design of beams for torsion includes the checking of the interaction with bending and shear. ASDIP CONCRETE generates all the required calculations per the ACI provisions.
The Design Manager is a tool that will design the reinforcement based on the specified loads and design criteria. This is intended to help the designer with a first trial of an optimum set of rebars. Then you can go to the Reinforcement tab and adjust the number of rebars and sizes as you see fit. The structural design process is a science, but it's also an art. As such, the preferences and experience of a crafted designer plays an important role.
The image below shows the Reinforcement tab and the generated shear and moment diagrams for the continuous beam. Note that the software shows the structural capacity in blue for visual comparison purposes.
ASDIP CONCRETE now includes the design of beams for torsion. The graphical user interface is simple and intuitive, with multiple options to optimize the design easily. The results are shown instantly in both text and graphics format.
For our collection of blog posts about concrete design please visit Structural Concrete Design.
Javier Encinas, PE
ASDIP Structural Software