PlenFrem Reviews

This is probably the only really freely available software which provides 2D frame and truss analysis without any node and member limit. Other similar software I tried are ridiculously limited to like 5 members or so. So kudos to developers for the great work. It offers a graphical interface where you can write node and member details for your structure. You can also import a DXF file, which I felt is great! The graphic is very basic. It shows only the structure geometry, node & member numbers, loads and support types. It does not show result of the analysis graphically. But hey, this is a free app. The "sample" folder has plenty of example structures (CSV files) with links to web pages so that you can get a head start. I also compared the results against some commercial programs and they matched, which inspires confidence. Their help file says their philosophy is to offer a plane frame/truss analysis program with no bells and whistles. which I think they have achieved. It is a single executable file with GUI and remarkably easy to use. Some larger structures (over hundreds of nodes) take few minutes to analyse though but it depends how fast your computer processors are. Plenfrem also shows step by step output of the calculation in the log file. So you can see stiffness matrix of each members, the global stiffness matrix etc. This feature is very helpful for if you are comparing against manual calculations or you are a student. There are few quirks though which I believe developers may look into future versions. Uniformly Distribute Loads are inserted using a separate grid under Edit - Add UDL menu. From there, it converts UDL to equivalent joint loads in node grid. You need to save this data separately (if you want) in description field (if you need them later). I have noticed that if your nodes have negative co-ordinates, it can't show the model (using View - Model) - although it does not affect analysis output. There is node offset function under Edit menu where it allows to add an offset to all X,Y coordinates so that these become positive values and after than model is displayed correctly.

free and powerful software, easy to use

Great software for structural analysis of plate frames and trusses.