Abstract
High-force-to-volume (HF2V) lead-extrusion energy dissipation devices have been demonstrated to be efficient, low-cost energy dissipators for managing structural seismic response energy to mitigate damage. They have been employed in full-scale structures, as well as demonstrated in a range of large-scale experiments and numerical structural analysis studies. However, they have proven difficult to precisely design to match a specific force capacity.This study develops a precision HF2V design model based on the sum of friction and extrusion forces modelled as a function of device dimensions. Specifically, the Area Ratio (AR), shaft Surface Area (SA), and Bulge Area (AB). Multiplicative coefficients for these terms in 14 linear and linear-quadratic models are calculated using regression analysis on data from 18 experimental devices with and without bulges. Pearson correlation coefficient values (R2) summarise model completeness and the error between experimental and model predicted force. Leave k = 3 out validation for random and specific groups of devices assesses model robustness to the device data used to identify the model.Model 2 (F = α0AR. Dcyl + α1SA) and Model 4 (F = α0AR. Dcyl + α1 SA + α2AB) have the best fit explaining all but 5% of the experimentally measured device force (R2 = 0.95). Overall, Model 4 predicts device forces better for a wide range of devices. Mean model prediction errors are 11%, and attributed to differences in device pre-stress, test velocity and experimental error. On average, the terms for AR and AB, capturing device extrusion force contributions to device force, contribute 65% and 13% of the total device force, with the remaining 22% due to friction, captured by the SA term.The overall results provide a simple generalisable model capturing all relevant mechanics for precise design of HF2V devices to a specific quasi-static force capacity, as well as a good starting point for more specific and detailed mechanics models.
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