Frequently Asked Questions (FAQs)

Real3D-Analysis - General

  • Is "Real3D-Analysis" just another structural analysis program?Real3D-Analysis is a comprehensive structural analysis and design program that is extremely accurate, reliable and user-friendly. It is NOT just another structural analysis program. In particular, it is NOT any of the following: an old program with just a new (poorly designed) Windows user interface; a new program that uses inefficient or unreliable frame or finite elements; a program that uses unreliable or inefficient proprietary "home-made" graphics; a program that is not enjoyable to use; a program that costs you too much.
  • How do I know "Real3D-Analysis" produces the correct results?The correctness of results is of utmost importance for a structural or finite element analysis program. This is implemented during various phases of the product development. Design Philosophy: Accuracy and reliability come before any other program features. Implementation: Only the most reliable frame and finite element formulations are used. These formulations are implemented in the most reliable algorithms and program language. Verification: Three methods are employed in the program verifications. a). Hand calculation. It is the most reliable method and is used whenever possible. b). Comparing with respectable published references such as MACNEAL, R.H., HARDER, R. L.; “A Proposed Standard Set of Problems to Test Finite Element Accuracy”, Finite Elements in Analysis and Design 1 (1985) 3-20, North-Holand. c). Comparing with other reputable finite element software such as ADINA. The verification examples in the program documentation are the typical testing problems. Many more problems were tested in-house.
  • How user-friendly is "Real3D-Analysis"?Many engineering software companies claim to have the most user-friendly software. This is certainly easy to say. You have to judge it (including Real3D-Analysis) for yourself. But try to ask yourself the following questions: Does the software have a simple, clean and consistent Graphical User Interface (GUI)? Does the software use a shaky (unreliable or inefficient proprietary) "home-made" graphics or the stable industry-strength graphics? Is it possible to create a simple model without the user's manual?
    Does the software produce dozens of different files with strange names when you perform an analysis?
    Does it look even like a normal Windows program?
    Are you looking forward to using that software again?
  • What is OpenGL(R) acceleration and why is it important?OpenGL(R) hardware acceleration refers to the graphic rendering through the graphic card in your computer. It is much faster than the graphic rendering provided by the operating system. Almost all graphic cards these days are OpenGL accelerated. If you happen to have an old graphic card that does not support OpenGL hardware acceleration, the program’s graphics may be significantly slower.
  • How do I know if my graphic card supports OpenGL(R) acceleration or not?To see whether your graphic card is OpenGL(R) accelerated or not, go to the program menu Help | About. If you can see "Installable Client Driver" in the about dialog box, then it is. Otherwise, it is not. It is important to point out that you may still run the program without OpenGL hardware acceleration. It is just slower, much slower.
  • I can not see the "Print" command from the File menu, why?The printing-related commands such as Print Preview or Print are not available in the Model View. They are available in the Report View after you run "Input/Output Report" or "View/Print Images". You may print a nice-looking report from the program. You may print an even better-looking report by copying the report and pasting it into your favorite word processor such as Microsoft Word. Remember to adjust the page margins (from File | Page Setup in Microsoft Word) before printing.
  • I can not run some commands after performing an analysis, why?This is most likely due to the automatic locking of the model. You may uncheck the option "Lock model after an analysis is performed successfully" from Settings | Preferences. Also, some data in spreadsheets may not be modified if this option is on or if you check the option "Show only selected entities in spreadsheet" in Settings | Data Options.
  • Why can't I select elements by mouse while viewing deflected shape of the model?This behavior is by design. To be able to select by mouse, you may set the displacement magnification factor to be 0 from View | Deflection Diagram or simply run View | Restore Model. This behavior does not happen when there are no results.
  • Are there any differences between the printed manual and the electronic (PDF) manual?The content of the printed manual should be exactly the same as that of the electronic manual. However, due to obvious reasons, the electronic file may be more up-to-date than the printed manual. You are therefore encouraged to use the electronic manual which is incidentally more environmentally friendly as well.
  • What programming language was used to develop Real3D-Analysis?Real3D-Analysis was written in its entirety in standardized C++, a programming language that is used in mission critical projects around the world. No FORTRAN, no Visual Basic, no C, no Java, no C#, no legacy code, period!
  • How many lines of code are there in the program?While many other programs claim to have tens of thousands, even millions of lines of code, as if the more the lines of code, the better the program. We believe that not. We strive to use fewer lines of code to produce more robust, more efficient program. To this end, we use such cutting edge technologies as generic programming, object-oriented programming, Microsoft Foundation Classes (MFC), OpenGL(R) and a programming language called C++.
  • When I run Real3D-Analysis on my Windows 2000, I got a dialog box saying "The procedure entry point IsWow64Process could not be located ... in kernel32.dll". Why?This is due to the presence of a different version of OpenGL32.dll on your system. You can correct this by renaming or removing the OpenGL32.dll under Real3D-Analysis installation directory.
  • What does "Real3D" in the program name stand for?"Real3D" stands for Real 3-Dimensional structures.

Real3D-Analysis - Modeling

  • What kinds of structures can the program analyze?Real3D-Analysis provides comprehensive frame and finite elements to analyze any practical structures. Examples are 2D or 3D trusses; 2D or 3D Frames; 2D or 3D plates and shells such as floors, mat foundations, shear walls, curved roof; water tanks, 3D solid structure. You may mix different types of elements in the model.
  • How big a model can the program handle?The capacity of Real3D-Analysis depends on the version you are running. Real3D-Analysis Professional sets no practical limit with regard to the number of nodes, elements etc. For example, the actual limit for the number of nodes is 231 - 1 = 2,147,483,647. However, your computer probably will run out of memory long before it reaches this limit. Other versions of Real3D-Analysis have capacity limitations deliberately imposed.
  • What is the 128-bit floating point solver?The 128-bit floating point solver refers to the solver that uses 128-bit (16-byte) floating point arithmetic. It is in contrast to the 64-bit floating point solvers that are the standard for virtually all other structural and finite element analysis programs today. Normally, the 64-bit solver produces satisfactory results for practical uses. However, under some ill-conditioned circumstances, such as when a model is very large or stiffness of elements varies greatly, the 64-bit solver may produce unreliable or even wrong results. The 128-bit solver is extremely accurate and provides an invaluable alternative to the standard 64-bit solver under such ill-conditioned circumstances.
  • Should I always use the 128-bit floating point solver?No. You normally use the 64-bit floating point solver. However, if significant number of digits is lost during the solving process or when solution becomes unstable, use the 128-bit solver. It is important to point out that the 128-bit solver uses twice as much memory as the 64-bit solver and is also significantly slower. However, between faster but wrong results and slower but correct results, you as a responsible engineer should choose the latter.
  • Can you give me an simple example where the standard 64-bit floating point solver would fail?Try a simple cantilever beam, fixed at the left end and loaded with a tip force at the right end. Model the beam with 20,000 or more elements. Do not consider shear deformation. The likelihood of wrong results from your familiar structural analysis program is very high. The 128-bit floating point solver in Real3D-Analysis will give you the correct results. For details, see Example 1 in the program documentation.
  • Can you give me a practical example where the 128-bit floating point solver would shine?Consider a floor with much larger in-plane stiffness than out-of-plane stiffness in a 3-dimensional building. Most of the other programs model this kind of rigid diaphragm action through master-slave constraints in order to avoid numerical difficulties. With the 128-bit floating point solver available in Real3D-Analysis, you may model the floor as a flexible diaphragm, yielding more realistic results.
  • How reliable is the thick plate (MITC4) bending element?There are literally dozens of plate elements available in different commercial structural or finite element programs. However, very few are both reliable and efficient. The MITC4 plate bending element is arguably the best plate bending element of its kind in the current state-of-the-art. It is shear lock-free and insensitive to distortion of element mesh. See the book "Finite Element Procedures" by K.J.Bathe, Prentice-Hall, Inc, 1996.
  • Can I model a thin plate with the MITC4 plate bending element?Absolutely. Although the MITC4 plate element uses the thick plate formulation, it may be used to model thin plates just as reliably. For a thin plate (t/L < 1/20), the MITC4 and classical Kirchhoff plate elements yield comparable results.
  • Does a thin plate have out-of-plane shear forces?Although the classical thin plate (Kirchhoff) formulation does not account for the out-of-plane shear deformations, out-of-plane shears do exist and are output by the program. To understand this, you may draw an analogy between a plate and a beam. A thin plate is analogous to a Euler-Bernoulli beam while a thick plate is analogous to a Timoshenko beam. We consider shear deformation for the Timoshenko beam but not for the Euler-Bernoulli beam, shear forces exist in both the Euler-Bernoulli and Timoshenko beams.
  • Can I insert another Real3D file into the current model?Not directly. You may export the other file to a DXF file and then import the DXF file to the current model. Only the geometry may be imported or exported. The geometry data are usually the most time-consuming input in the model creation.
  • Can I open files created in another structural analysis program?No. Real3D-Analysis does not provide import facilities for files created in other structural analysis programs. However, you may use DXF file export facility in the other program and DXF file import facility in Real3D-Analysis to share geometry data.

Real3D-Analysis - Tips

  • Speed-up graphics Although Real3D-Analysis uses the most advanced graphics technology, graphics may still take considerable computing time and memory, especially for large models. One useful and practical way to speed up graphics is to minimize the amount of graphics and to display only those that you need to see. For example, annotate only the interested items on selected elements, show loads for selected load cases, freeze uninterested parts of the structure altogether, etc.
  • CPU vs. RAM It is always a good idea to use the latest hardware to perform structural analysis, especially for large models. However, it is usually more economical to have as much RAM as possible than to have the fastest CPU. For example, a computer with a CPU of 500 MHZ and a RAM of 526 MB is more suitable to solve larger models than a computer with a CPU of 2 GHZ and a RAM of 128 MB.  When the solver needs more computer memory than available RAM, solution speed may be significantly slowed down due to the very time-consuming and frequent swapping of data between RAM and hard-disk.

RcSections - General

  • What is "RcSections"?RcSections is a powerful 32-bit Windows program designed specifically for structural engineers to perform Exact axial-flexural analysis and design of concrete sections (beams, columns or walls) according to ACI 318-99 -02 and -05.
  • Why are results not saved when I save a RcSections (verification example) file?RcSections saves the results by default when you save a file. However, you have the option (from the menu Settings | Data Options) to save the input only each time you save the file. This option is used for all verification examples and the tutorial to make the setup footprint small.

RcSections - Modeling

  • Why does RcSections analyze a uniaxial problem biaxially? RcSections always analyzes a section biaxially due to the uniform approach in its solution algorithm. For a section subjected uniaxial bending, you should input the biaxial angle steps found in the solver option dialog box to be 4. The program will solve for P-Mx(+) and P-Mx(-) capacity in the major axis bending, and for P-My(+) and P-My(-) capacity in the minor axis bending.
  • How accurate is the solution?How fast is the solution? The solution accuracy and speed depend on the solution parameters such as neutral axis steps and biaxial angle steps in the solver options. Generally speaking, more accurate solution requires more solution time. RcSections implements an unique solver that can very accurately solve hundreds even thousands of sections uniaxially or biaxially in seconds.
  • How many neutral axis steps should I set in the solver option?This depends on the problem you are solving. For regular sections, a value of 250 - 500 is generally accurate enough for practical applications. The adequacy of neutral axis steps can be determined by the smoothness of the P-Mx and/or P-My interaction diagram.
  • How many biaxial angle steps should I set in the solver option?This again depends on the problem you are solving. For a regular section, a value of 16 - 32 is generally accurate enough for practical applications. The adequacy of biaxial angle steps can be determined by the smoothness of the Mx - My contour diagram. A low value of biaxial angle steps tends to give more conservative biaxial capacity for the section.
  • Why doesn't the program have a design option?There is no need to provide a design option in the program thanks to its ability to solve multiple sections simultaneously. The design of concrete section embodies at least the following two features: 1). It is a trial-and-error process. 2). More than one solution may be equally plausible. The program recognize this and tries to alleviate the pain of the trial-and-error process while at the same time does not pretend to be too smart to present you with a single final design section. The section generation facility in the program makes it a breeze to parametrically generate (and therefore try) tens, hundreds even thousands of sections with different dimensions and reinforcement layouts. This, combined with the blazingly fast solver, makes it very easy to design a uniaxial or biaxial loaded section. More often than not, you are presented with the opportunity to pick up from among several and equally plausible section candidates. This is the beauty of a good engineering software: It takes off the drudgery of calculation from you but does not deprive you the ability to make sound engineering judgments.
  • How can I adjust the aspect ratio of P-Mx interaction diagram?First, activate the P-Mx interaction diagram view. Then go to menu View | Diagram Type and change the P-M diagram aspect ratio in the dialog box. Also by changing force and moment units, the P-M aspect ratio changes accordingly.
  • Can I annotate the points used in the P-Mx interaction diagram and other result diagrams?The program annotates some key points such as balanced point and pure bending point automatically when you first launch the P-Mx or other result diagrams. To annotate additional points, simply point and click the points with the mouse, or click and drag the mouse to annotate multiple points. To turn the annotations off, press ESC key.
  • Where can I get the result data so that I may construct my own P-Mx interaction diagram in my favorite spreadsheet program?All result data used to construct P-Mx and other result diagrams are transparent to the user from the main menu Result Data. These data are presented in the spreadsheet and are easy to be copied to other spreadsheet program. To copy data from RcSections spreadsheets, just use your familiar keys CTRL+C, CTRL+V.
  • How can I see loads inside the P-Mx_My interaction surface?The P-Mx-My interaction diagram is opaque at this time. However, you have an option to view it as wire-frame so that all loads can be seen. To do that, use menu Settings | Preferences and unselect the option "Show 3D surface (instead of wire frame) for P-Mx-My curve".
  • Does the program accounts for slenderness effects?At this moment, RcSections does NOT account for slenderness effects as specified in the documentation. The program assumes that the input loads are factored loads including any moment magnification if necessary. According to ACI, two approaches may be used to account for slenderness effects. 1). Approximate moment magnification method. 2). Second-order (P-Delta) analysis. The second method is recommended over the first one by ACI and is required when kL/r is greater than 100. Many structural analysis program, including Real3D-Analysis, have P-Delta analysis options. The slenderness effects are important. However, RcSections assumes that they are taken care of outside the program.