Apps similar to Estru3D include SAP2000. It's paid, but FRAMEWORK 2D+3D and Structurix are free. Other options are St, MASTAN2, Analysis for Windows and sas-civil. You're spoiled for choice with apps like Estru3D: we list more than 25 alternatives for Windows, Mac and Linux.
Diamonds is the perfect software for structural design analysis of beam grids, floor slabs, rafts, walls, frames and multi-storey buildings, ... in concrete or steel. Development of calculation engineering design software with powerfull tools en simple user interfaces
Want bridge software that does it all? Try OpenBridge Modeler, Bentley's 3D parametric modeling, analysis, and load rating software for bridges.
DIANA is an extensive multi-purpose finite element software package that is dedicated, to a wide range of problems arising in Civil engineering including structural, geotechnical, tunnelling, earthquake disciplines and oil & gas engineering.
