https://repo.nzsee.org.nz/xmlui/handle/nzsee/1614 2020 Sun, 19 Apr 2026 01:22:35 GMT 2026-04-19T01:22:35Z http://https://repo.nzsee.org.nz:8080/bitstream/id/2b7b1c25-2440-458d-8939-ef8c5301c2e7/ https://repo.nzsee.org.nz/xmlui/handle/nzsee/1614 https://repo.nzsee.org.nz/xmlui/handle/nzsee/1755 Finite element method for designing HF2V device force capacity Vishnupriya, Vishnupriya; Chase, James Geoffrey; Rodgers, Geoffrey; Zhou, Cong Supplemental energy dissipation devices are increasingly used to protect structures, limiting loads transferred to structural elements and absorbing significant response energy without sacrificial structural damage. High force to volume (HF2V) dampers are supplemental energy dissipation devices, which have previously been designed using relatively low-precision models, creating significant design uncertainty and requiring an inefficient build-test approach. Further, knowledge of the internal mechanics of the lead and bulged shaft, which result in the device force, is lacking, limiting predictive accuracy in device design. This paper presents a more precise, finite-element based, method of predicting device resistive forces based on any given device geometry. Dimensions for 15 experimental HF2V devices tests are applied to a 2D axisymmetric large-deformation finite element model with adaptive meshing, developed using ABAQUS. Resistive forces are produced during the quasi-static displacement of the shaft within the HF2V devices. Total device force is achieved by summing contact pressure forces including the normal and friction forces on the lead along the shaft. Results of these highly nonlinear, high strain analyses are compared to experimental device force results. The force-displacement plots are made from the force-time response obtained from the finite element analysis. Model force-displacement plots exhibit good prediction capacity corresponding to experimental results. Errors between model and experimental results for all 15 devices ranged from -8% (over-prediction) to +20% (under-prediction) with a mean absolute error of 5.9%. The hysteresis plots from the FE models match the experimental force-displacement curves. The overall FEM approach is objective, repeatable, and thus generalisable. Low error validates the overall approach, and thus the general modeling methodology for accurate HF2V device design presented. Wed, 22 Apr 2020 00:00:00 GMT https://repo.nzsee.org.nz/xmlui/handle/nzsee/1755 2020-04-22T00:00:00Z https://repo.nzsee.org.nz/xmlui/handle/nzsee/1753 Shear Wall Design Tool - Structural Engineering Design Society NZ (SESOC) Bird, Geoff; McPherson, Allan SESOC has, over a period of time, developed and acquired a number of structural software design programs. This paper will preview a new development, namely “Gen-Wall”, a software program developed specifically for the design of reinforced concrete (RC) shear walls to NZS 3101. It also briefly overviews the other SESOC software, including the recently launched MemDes+ software. Wed, 22 Apr 2020 00:00:00 GMT https://repo.nzsee.org.nz/xmlui/handle/nzsee/1753 2020-04-22T00:00:00Z https://repo.nzsee.org.nz/xmlui/handle/nzsee/1754 Influence of ground motion orientation on predicted seismic compression Green, Russell; Bahrampouri, Mahdi Seismic compression is the accrual of contractive volumetric strain in unsaturated or partially saturated sandy soils during earthquake shaking and has caused significant distress to overlying and nearby structures. The phenomenon can be well-characterized by load-dependent, interaction macro-level fatigue theories, which means that the nature of the accumulation of volumetric strain is a function of the absolute amplitude and sequencing of pulses in the loading function. One model that captures this behavior and that can be used to predict seismic compression is the expanded Byrne cyclic shear-volumetric strain coupling model. However, one potential implication of the load-dependent, interaction macro-level fatigue behaviour is that ground motion orientation will influence predicted settlements. To examine the significance of this, the seismic compression that occurred at the Kashiwazaki-Kariwa Nuclear Power Plant (KKNPP) site during the 2007, Mw6.6 Niigata-ken Chuetsu-oki, Japan, earthquake is analyzed using the expanded Byrne model. The horizontal motions recorded at the site by a down-hole array during this event are rotated in 5° increments and the predicted settlements due to seismic compression are computed. The predicted settlements range from 12.3 to 16.1 cm, with a geometric mean of the values for various orientations being 13.8 cm. These results are in general accord with the post-earthquake field observations and highlight the sensitivity of predicted magnitude of the seismic compression to ground motion orientation. Wed, 22 Apr 2020 00:00:00 GMT https://repo.nzsee.org.nz/xmlui/handle/nzsee/1754 2020-04-22T00:00:00Z https://repo.nzsee.org.nz/xmlui/handle/nzsee/1751 Cyclic tests of an innovative seismic bracing member - multiple U-shaped flexural plates dissipater Chen, Yan; Palermo, Alessandro; Mashal, Mustafa Following Canterbury earthquake sequence, there has been an increasing interest in development of low-damage structural design using supplemental damping such as the use of metallic dissipaters. In this research, an innovative seismic bracing member called multiple U-shaped flexural plates (UFP) dissipater (MUD) is proposed. It consists of two rows of UFPs bolted to an internal member and inserted inside a casing. The internal and external members move relative to each other under axial compression and tension loading. Energy dissipation comes from plastic deformation (rolling deformation) of the UFPs. A series of quasi-static cyclic tests were conducted with different arrangements of UFPs and various loading sequences. The mechanical properties, hysteretic characteristics and strength degradation of MUD were investigated. All specimens completed the cycles of displacement corresponding to a 2.8% story drift ratio. The dissipater exhibited stable force-displacement hysteresis and high energy dissipation capacity. Specimen 1, 2 and 3 have been through 28 loading cycles without significant degradation of strength. Specimen 4 has been through three times the maximum credible earthquakes and 46 loading cycles at 2% inter-storey drift ratio (corresponding to a diagonally braced frame with a storey height of 3.0m and a bay length of 3.1m). There was no significant degradation of strength until the last 10 loading cycles where the strength and stiffness started to reduce moderately due to cracking of UFPs. Wed, 22 Apr 2020 00:00:00 GMT https://repo.nzsee.org.nz/xmlui/handle/nzsee/1751 2020-04-22T00:00:00Z