Structural analysis tools have been created ever since the development of early computers because these allow for rapid solution of complicated structural problems in the fraction of the time required to do hand calculations. The initial tools were very basic in both functionality and performance offered by the computers in the past. However, over time, comprehensive software was developed, and modern structural applications now offer full analysis, design and optimisation solutions helping engineers rapidly prepare designs of very complex structures. The advances in structural analysis now enable engineers to analyse structures that even 15 years ago would not have been possible to model and design accurately. Most of the existing tools were developed in low-level languages such as Java or C++ and remain PC based.
When looking at the literature on computer based structural analysis and the stiffness method a lot of guidance and code is available in Fortran, Basic, C and Java. Software developed using these programming languages is tied to the hardware and the operating system that it has been compiled and developed for and porting such applications to different platforms is often very difficult.
A good number of Java based structural analysis tools have also been developed in the past and some books have been published on the topic. Whilst significantly more portable, Java applications require that a Java Virtual Machine (JVM) be installed on the computer to be able to run which can be cumbersome, and many user choose not to (or don’t know how to) have it installed. There is a wealth of information on programming structural analysis software in Java, and a book Programming Finite Elements in Java (Nikishkov, 2010) provides extensive guidance. Some of the chapters from this book can be applied to this project.
There are many structural analysis (and design) packages available on the market. Unlike many markets where individual players have managed to achieve very large market share, and set their software as de-facto industry standards, the market for structural analysis software is still very much fragmented with many options available. In addition, many larger practices still maintain and develop their in-house structural software.
Most of the original software developed in the 80s was very basic, had non-existent or very basic graphical output and often only textual data input and included a very limited array of elements. The 90s saw the development of full graphical interfaces that allowed for much easier modelling of structures. The functionality of software was expanded to include non-linear analysis, flexible supports, movable loads, load combinations, etc. The software popular at the time included SAAP, STAD and many others.
In the past 10 years, the development in commercial software has concentrated mostly on improving the usability and functionality of the software, with features such as solids and slab analysis (incl. plate and solid elements) and dynamic analysis of structures becoming standard in many packages (although rarely at entry-level prices). Furthermore, most packages have been expanded to include element sizing and design (in steel, timber, RC) and often allow some form of graphical output into CAD. Building Information Modelling (BIM) has saw great expansion and adoption in the past 2-3 years, and the latest tools from Autodesk and Bentley tie into their BIM systems allowing for improved cooperation between various disciplines involved in the design of a building. A short table listing some of the currently popular software listing their functionality is included below:
|
Software |
Licence |
Developer /Publisher |
Platform |
Capabilities |
|
Commercial |
Autodesk |
PC, Mac |
Structural modelling + analysis of structures; Full BIM support to integrate with other disciplines; Design and drafting tools |
|
|
Commercial |
Autodesk |
PC + cloud storage |
Revit add-on; Performs analysis off-site in the cloud to boost performance. Requires PC structure to input data and view results |
|
|
Commercial |
Autodesk |
PC |
A popular and feature-rich analysis and design package incl. non-linear analysis, dynamic analysis, many types of elements, etc. Links with Revit; |
|
|
Commercial |
Bentley |
PC |
Full-featured structural analysis tool which includes non-linear analysis, dynamic analysis etc. Links with RAM and ProSteel for steel sizing and detailing and with Bentley’s BIM tools. |
|
|
Commercial |
CSI |
PC |
One of the most comprehensive 2D and 3D structural analysis packages. The interface is difficult to master for new users, but functionality is comprehensive. Extensive choice of 1D, 2D and 3D elements and analysis modes. |
|
|
Commercial |
Dassault Systemes |
PC / Windows |
supports multiple stages of product development (CAx), including conceptualization, design (CAD), manufacturing (CAM), and engineering (CAE). |
|
|
Commercial |
Radimpex |
PC / Windows |
Offers 3D analysis of linear and plate elements; Non-linear and dynamic analysis. Concrete, steel and timber sizing to many codes. Links to proprietary steel and RC detailing tools. |
The list above is by no means extensive or complete. Another non-complete list of finite element packages is available on Wikipedia (Wikipedia, 2013).
A recent trend in software development in general is to create web-based applications that utilise JavaScript scripting language combined with html5 markup language. Whilst more resource intensive than natively compiled applications these allow for great hardware and software portability and are capable of running in most modern browsers and can easily be compiled into full-fledged applications for iOS, Android and Windows 8. In particular, the introduction of the Canvas element and SVG (Scalable Vector Graphics) in the recent years has enabled the development of graphics-rich web applications making it possible to create web-based full-featured structural analysis tools which require graphical input and representation of results.
The author has not been able to find any purely web-based structural analysis tools, however good examples of fully web-based productivity tools include Google mail and docs, Microsoft’s Office 365 (Office web apps), Apple’s iWorks, and AutoCAD WS. Such application run within a web-browser and store the information in a cloud making it available from a variety of devices and allow for very easy access.
A Wikipedia definition of structural analysis states: “Structural analysis is the determination of the effects of loads on physical structures and their components. “ (Wikipedia, n.d.). It also provides a very good Timeline showing the historical development of structural analysis methods.
Whilst simple single beam and small assembly problems can be solved directly, the analysis of structurally indeterminate structures is more complex. There are three main approaches to solving linear, elastic frame analysis problems. These are Flexibility Method, Stiffness Method, and a particular variation of stiffness method – Moment Distribution.
Of the three methods, all have their advantages in particular situations, and for solving particular problems. The Flexibility method is particularly useful in solving problems that include frames with a low learn7-programming-finite-elements-in-javascript.htm of static indeterminacy. The Stiffness method is suitable for hand calculations where structure has a lower learn7-programming-finite-elements-in-javascript.htm of kinematic than static indeterminacy. Moment distribution is a widely used and convenient method for solving complicated problems without the need to set up a large number of simultaneous equations. It is also a convenient method of checking computer output.
Konstrct.com utilises the stiffness methods to resolve deformations and member forces within the analysed structure. Thus, the documentation available here concentrates on detailing this method.