PLASTIC BENDING OF PORTALS
The experiment hardware fits onto a Structures Test Frame (STR1, available separately). Students fix a specimen portal frame (two uprights with a cross-beam at the top) to the bottom cross-piece of a test frame. The test frame also holds horizontal and vertical screw mechanisms with electronic load cells for loading the portal frame. Students set the portal frame load conditions by arranging the load cell screw mechanisms to provide either single or combined loads. They then load the portal frame manually by adjusting the screw mechanisms. The electronic load cells connect to a Digital Force Display (STR1a, available separately) that shows the horizontal and vertical loads as the portal frame deforms. Two long-travel digital deflection indicators measure the portal frame deformation.
Students continue to load the portal frame until it is in the fully plastic condition, that is, it has undergone plastic collapse. They monitor the collapse load, deformations, and note where plastic hinges formed during collapse. Packs containing 12 extra specimen portal frames are available separately (STR16a).
Ideally, students should use the Plastic Bending of Beams experiment (STR15) before progressing to Plastic Bending of Portals. The Plastic Bending of Beams experiment provides a basic understanding of underlying principles, such as plastic deformation and form factor.
The lecturer guide provides details of the equipment including sample experiment results. The student guide describes how to use the equipment and gives experiment procedures.
For extra ‘virtual’ experiments, TecQuipment can supply the optional TecQuipment Structures Software (STRS), for use on a suitable computer. The virtual experiments simulate the tests you can perform with the hardware. They also extend the choice of tests beyond that available using only the hardware, for example: higher loads, uniform loads or different test specimens. This extends the student’s learning experience.
For automatic data acquisition of your experiment results, TecQuipment can supply the optional Automatic Data Acquisition Unit (STR2000). Supplied as standard with the STR2000 is TecQuipment’s Structures Software that displays and logs your experiment results and gives the extra virtual experiments.
- Relationship between load and deflection for portal frames loaded to the plastic condition
- Introduction to limit state design
- Relationship between maximum loading and plastic hinge formation in portal frames loaded vertically from the centre, horizontally from one corner, and equally from both positions
- Interaction between horizontal and vertical loading in terms of plastic hinge position and mode of collapse