Buckling Matters – Rotational Spring Supports

Exceptionally tall or slender columns may necessitate finite element modelling to determine the effects of buckling. However, in many cases an accurate assessment of the critical buckling load can be made by hand calculations incorporating spring supports or tapered/stepped stiffness columns. This paper discusses the calculation of the buckling load for the end conditions given in Eurocode 2, including various rotational spring restraints and variable stiffness within the length of the strut.

Simplified Dynamic Analysis of Beams and Slabs with Tuned Mass Dampers

This paper simplifies the analysis of the dynamic response of structures to a sinusoidal loading to provide arithmetic solutions and a means of understanding the dynamic response of a structure. It also provides a means to estimate the characteristics (mass, stiffness and damping) of a TMD to address any residual problematic dynamic response. This enables the design provision for the additional weight attached to the structure and the required space, if a TMD is deemed to be necessary. A worked example of a simply supported welded steel box girder footbridge is presented.

Retrofitting Eagles Meadow Bridge with a Tuned Mass Damper

This paper presents a solution to undesirable acceleration effects experienced by pedestrians on the Eagles Meadow Footbridge in Wrexham. The installation of a tuned mass damper reduced the vertical movement of the bridge to near imperceptible levels. An analysis by hand calculation of the bridge dynamics and tuned mass damper characteristics is presented.