Introduction to DCALC

Transcription

1 Chapter 1: By Karl Hanson, S.E., P.E. August Introduction: DCALC, an acronym for DesignCALCs, is a collection of structural engineering software. This chapter is an overview of DCALC, describing what it is and how to use it. This will not be your typical computer manual. In addition to showing the user examples of how to use DCALC, I hope to dispense design tips and my opinions about structural engineering. I have chosen to write in casual first person style for this part of the tutorial. I believe this style is an effective method of communication for purposes such as this. Occasionally, tidbits of advice will be inserted, such as the following: Try to think of DCALC as a dynamic book a book of calculations that is written by somebody else. Read and understand the calculations! Part of the intent in this manual is to instill some perspective on how engineering is changing. Engineering software packages, such as DCALC, fit into this picture in a big way. Chapter 2, How Engineering Software Has Changed The Way We Work explains my thoughts. DCALC can do a whole lot of calculations, but you re the designer, and you must understand those calculations. Structural engineering entails a great responsibility. Engineering software is a tool to be used by engineers - like a hammer is to a carpenter. 1.2 The Development of DCALC (the short version): There is a saying: The only way to eat an elephant is one bite at a time. DCALC did not happen overnight. DCALC was originally marketed as a DOS program for bridge engineers in the Midwest since The programs were written by myself as a way to automate my own calculations. It has had loyal following through the years, particularly in Illinois where I work. Many firms still us the DOS version. Early in my engineering career, I felt overwhelmed by the number of codes I needed to learn. I was also frustrated doing repetitive hand calculations, thinking there could be a faster way. With the introduction of personal computers and spreadsheet programs, like Lotus 123 and, later, Excel, the way engineers prepare calculations changed radically. I envisioned a need for an application better than a spreadsheet, that would integrate text and graphics, tailored to my own needs. Beginning in the late 1980 s I began developing a system for writing programs that automate calculations. Eventually I developed a CASE type tool (which stands for Computer Added Software Engineering a code generator), enabling me to write a lot of code very quickly. I still use the same tools, which I have currently adapted to Microsoft Visual Basic, to write DCALC. p. 1-1

2 1.3 Installing DCALC: If you ve gotten this far, I assume that you already have DCALC installed on your computer. However, if not, these are the installation instructions: DCALC is installed from the DesignCalcs website located at You will need to do the following: 1. Download the DCALC demo 2. Fax the completed license agreement to the number on the license agreement 3. Upon receipt of payment, installation instructions will be ed to you. Each computer with DCALC installed will require web access for the installation process. The full operation for DCALC requires an activation code, which will be ed to you, which is specific to each computer. If you need to install DCALC on a different computer (say your hard drive crashes): Remove DCALC from the original computer, if possible Contact DesignCalcs and request another activation code. p. 1-2

3 1.4 Starting DCALC: Upon opening DCALC you will see the following screen, This is followed by a disclaimer, describing your responsibilities (which I ve so thoroughly elaborated on in the previous sections!): This is followed by the main menu: p. 1-3

4 1.5 The Job Directory: The Job Directory is the directory where a project s DCALC calculations reside. You will see that after installing DCALC that the job directory is C:\DCALC\DEMO. There are many example calculations in this directory that the tutorials discuss in detail. Most of the examples should be self-explanatory. If you have multiple copies of DCALC and you are working on a network, I suggest that you create a DCALC calculation directory in your project file on the network. You will need to create a job directory using one of two methods: 1. Create a directory using Windows Explorer 2. Or create a directory using DCALC, after clicking on the Enter Job Directory command button As an example, let s say that your firm s network has a project directory located at H:\02060, and your structural department files are typically located in a STRUC subdirectory. I suggest that you make another subdirectory, H:\02060\STRUC\CALC where you will store your files. Each computer using DCALC maintains a record of the current directory where the calculations are stored. The Enter Job Directory command button is used to navigate through job directories. After clicking on Enter Job Directory you will see something like this: In the above screen, you will see that someone created a directory to store calculations for PPC Beam Studies. Note also the field for Designer s Initial s. These initials will automatically be placed in your calculations. p. 1-4

5 1.6 Making A Calculation: Going back to the main menu, calculations are started by selecting Make A Calculation. You then see the following screen: The View Bridge Design Flowchart option is discussed in the Tutorial Designing Steel Bridges Using DCALC. After clicking on View All DCALC Programs you will see the following screen: The calculations are grouped in broad logical categories according to materials types and structural systems. p. 1-5

6 1.7 Running a Calculation: All of the calculations have similar introductory screens, asking for calculation header information, such as the following: You will be typically asked to either Proceed or Exit. Note that Exit will get you all the way out of a program; that is, there is no reverse stepping through the process. Simply click on Proceed and the programs will walk you through all of the steps. After going through the process of providing input, each calculation will present a screen for entering the name of the calculation title, such as the following: The description that you enter will appear in the calculation title. You can write a calculation as long as necessary (as long as it fits on the line), similar to a hand calculation. p. 1-6

7 (You don t really need to know this, but ) DCALC has its own system of storing files internally. All DCALC files are numbered sequentially, DCALC1, DCALC2, etc. Try not to mess with these files! Also, there is no need to copy files or change names using Windows Explorer; use DCALC s Calculation Manager instead. 1.8 Viewing and Printing Your Calculation: After you ve run a calculation, you will want to see the results. On the main menu, click on View/Print Calculation. You will then see something like the following screen: After clicking on the calculation, you will see your calcs. Calculations are printed using the print option. 1.9 Edit An Output File: Most of the calculations write an output file that other programs can read. For example, the CAD splice detail is prepared by a special program that reads the output file that was prepared by the splice calculation program. Similarly, the CAD bearing detail is prepared by a special program that reads the output file prepared by the bearing calculation program. Equally important, output files are read by the various calculations programs to construct input. For example, the splice calculation program gets beam dimensions from the output file written by the beam design program. In this way, output files allow programs to prepare input based on another program s output; another term for this is software integration. Collectively the output files represent a database. Representing structures using databases is the present and future trend in structural engineering. Carried to a logical conclusion, it p. 1-7

8 is with no doubt possible to transfer database information to the fabricator. In fact, some firms are doing just that to a limited extent with steel fabrication drawings. Presently, there are a several different standardized formats for structural databases used in the world. DCALC uses it s own simple format for identifying information shown in an output file. You can view an output file by clicking on the Edit Output File command on the main menu. The above output file is taken from a calculation generated by BRIJBEAM. You may never need to edit this information, however this capability has been incorporated into DCALC. p. 1-8

9 1.10 Calculation Manager: DCALC has its own internal file manager that must be used rather than Windows Explorer. The reason for this is because each calculation has multiple files associated with it (input, output and CAD files). The DCALC Calculation Manager was specifically written to work with the logic of DCALC s file structure. Upon clicking on Calculation Manager you will see a screen similar to the following: On the left side of the screen are the file names that you can Erase or Change Title. Files on the left side can be copied to a different directory by doing the following: 1. On the right side, navigate to the directory where you need to copy a file 2. On the left side, click (highlight) the file that you need to copy 3. On the left side, click on Copy To You will then see that the file has been copied to the directory on the right side. p. 1-9

10 1.11 Mailing and Receiving Calculations If you need to send a set of calculations to another office or another computer, you will need to package the set of calculations using the Mail/Receive Calcs option command in the main menu. Do not use Windows Explorer to calculations unless you are sending all of the calculations in a directory. Use DCALC s Mail/Receive Calcs option, which was specifically written knowing DCALC s internal file structure. After clicking on Mail/Receive Calcs, you will see the following screen: If you select to package calculations, you will see the following screen: Here two files are checked to be mailed. After packaging, you can the package using Microsoft Outlook or Windows Explorer. On the receiving end, the package will need to be unwrapped using Mail/Receive Calcs. p. 1-10

11 1.12 Make a CAD Detail: Many of the DCALC s calculations interface with DesignCAD, a CAD software package marketed by IMSI ( You will need to purchase of copy of DesignCAD in order to produce the automated CAD details made by DCALC. I have personally used DesignCAD since about I also use AutoCAD and MicroStation, although I m much less efficient. Drawings can be imported and exported between these CAD packages fairly easily. (There is a story behind why I chose to interface with DesignCAD: It has the easiest programming interface of any CAD software I ve run across. The program was originally developed by some very smart people in Pryor, Oklahoma. The beauty of this program never ceases to amaze me!). The following DesignCAD details were generated by DCALC. Below is a detail showing a girder splice: p. 1-11

12 Below is another detail automatically generated by DCALC showing a bearing: The above details were imported into MicroStation, with minor editing required. The automated detailing capabilities of DCALC are impressive time savers. However, you will need to look over the details, because editing is usually necessary. Even though editing is typically required, these details can give you a big head start. (Imagine drawing all of the bolts in the splice detail, for example!) Details are drawn to scale, giving you a real picture of what you are designing Download Updates: DCALC is a dynamic program, continuously being upgraded and edited. Firms can periodically download the latest updates during the terms of their license. After clicking on Download Updates, you will be directed to the DesignCalcs Website. This website will have all the latest versions of DCALC programs. You can download a self-extracting zipped file of the latest programs in one package. This option becomes disabled after the term of the license expires. p. 1-12