scholarly journals The Effect of Reinforcing Plate on the Stiffness of Elastomeric Bearing for FPSO

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6640
Author(s):  
DongSeop Han ◽  
MooHyun Kim

The marine elastomeric bearing consists of an elastomer and several reinforcing inserted plates. Unlike land bearings that are to absorb high-frequency vibration during earthquakes, offshore elastomeric bearings are to support topside-module weight while efficiently absorbing wave-induced hull motions. The bearing is to receive three loads: compression, shear, and bending, and providing sufficient stiffness to resist the loads by inserting an adequate number of reinforcing plates is a major design issue for marine bearings. The stiffness of elastomeric bearings is largely influenced by the ratio of height to the area of the bearing and the number of laminated reinforcing plates. In this study, for the given size of the elastomeric bearing, the effect of the number of reinforcing plates on its compression, shear, and bending stiffness is investigated by using ANSYS Mechanical APDL, a commercial structural FE (finite element) analysis program. First, full analysis is done for the compression, shear, and bending stiffness with increasing respective displacements and the number of reinforcing plates from 0 to 8. The numerical results are partly validated by authors’ experimental results. Based on the numerical results, several empirical formulas are suggested for the variation of the three stiffnesses as a function of the number of reinforcing plates. Next, the design of the elastomer bearing for a representative FPSO (Floating Production Storage and Offloading) operated in the North Sea is conducted according to the required load and displacement conditions. Then, the adequate number of reinforcing plates for the case is determined and the results are shown to satisfy all the required safety factors for various required loading conditions.

2021 ◽  
Vol 5 (7) ◽  
pp. 170
Author(s):  
Pablo Castillo Ruano ◽  
Alfred Strauss

In recent years, interest in low-cost seismic isolation systems has increased. The replacement of the steel reinforcement in conventional elastomeric bearings for a carbon fiber reinforcement is a possible solution and has garnered increasing attention. To investigate the response of fiber-reinforced elastomeric bearings (FREBs) under seismic loads, it is fundamental to understand its mechanical behavior under combined vertical and horizontal loads. An experimental investigation of the components presents complexities due to the high loads and displacements tested. The use of a finite element analysis can save time and resources by avoiding partially expensive experimental campaigns and by extending the number of geometries and topologies to be analyzed. In this work, a numerical model for carbon fiber-reinforced bearings is implemented, calibrated, and validated and a set of virtual experiments is designed to investigate the behavior of the bearings under combined compressive and lateral loading. Special focus is paid to detailed modeling of the constituent materials. The elastomeric matrix is modeled using a phenomenological rheological model based on the hyperelastic formulation developed by Yeoh and nonlinear viscoelasticity. The model aims to account for the hysteretic nonlinear hyper-viscoelastic behavior using a rheological formulation that takes into consideration hyperelasticity and nonlinear viscoelasticity and is calibrated using a series of experiments, including uniaxial tension tests, planar tests, and relaxation tests. Special interest is paid to capturing the energy dissipated in the unbonded fiber-reinforced elastomeric bearing in an accurate manner. The agreement between the numerical results and the experimental data is assessed, and the influence of parameters such as shape factor, aspect ratio, vertical pressure, and fiber reinforcement orientation on stress distribution in the bearings as well as in the mechanical properties is discussed.


2018 ◽  
Vol 7 (3.10) ◽  
pp. 94
Author(s):  
T Subramani ◽  
V Sukumar

Castellated beam is escalation in vertical bending stiffness, simple carrier provision and appealing look. But one effect of presence of Web beginning will be the development of varied local results. Castellated beams are metal beams with web openings and that they benefit its benefit because of its multiplied depth of phase without any extra weight. To analyze the conduct of castellated metal beams having an I-shaped go-element. Analysis is carried from beam with two factor load and genuinely supported assist condition.  


2016 ◽  
Vol 67 (1) ◽  
pp. 81-101 ◽  
Author(s):  
Joanna Staneva ◽  
Victor Alari ◽  
Øyvind Breivik ◽  
Jean-Raymond Bidlot ◽  
Kristian Mogensen

2011 ◽  
Vol 291-294 ◽  
pp. 3282-3286 ◽  
Author(s):  
Jiang Wei Wu ◽  
Peng Wang

In port crane industry, the surface hardening technique is widely used in order to improve the strength of wheel. But the hardening depth is chosen only by according to the experience, and the effect of different hardened depths is not studied theoretically. In this paper, the contact stresses in wheel with different hardening depth have been analyzed by applying three-dimensional finite element model. Based on this model, the ANSYS10.0 finite element software is used. The elastic wheel is used to verify the numerical results with the Hertz’s theory. Three different hardening depths, namely 10mm, 25mm and whole hardened wheel, under three different vertical loads were applied. The effect of hardening depth of a surface hardened wheel is discussed by comparing the contact stresses and contact areas from the numerical results.


2020 ◽  
pp. 136943322096527
Author(s):  
Longji Dang ◽  
Rui Pang ◽  
Rui Liu ◽  
Hongmei Ni ◽  
Shuting Liang

This paper aims to investigate the seismic performance of hollow floor interior slab-column connection (HFISC). In this new connection system, several tube fillers are placed in slab to form hollow concrete. Moreover, locally solid zone, shear components, and hidden beam around the connections are installed to improve the bearing capacity and ductility of specimens. Three slab-column connections with different shear components were tested under cyclic loading and every specimen was constructed with parallel tube fillers in the north direction and orthogonal tube fillers in the south direction. The seismic behavior of specimens was evaluated according to the hysteretic response, skeleton curve, ductility, stiffness degradation, and energy dissipation. A finite element model was then developed and validated by a comparison with the experimental results. Based on experimental results and finite element analysis results, the relative effects of the hollow ratio of slab, the ratio of longitudinal reinforcement, the shear area of bent-up steel bars, and the arm length of welding section steel cross bridging were elucidated through parametric studies. This new slab-column connection showed better plastic deformation capacity while the bearing capacity was kept. Specimens with parallel tube fillers showed better seismic behavior than those of specimens with orthogonal tube fillers.


2019 ◽  
Vol 81 (6) ◽  
Author(s):  
Kai Siong Woon ◽  
Farzad Hejazi ◽  
Mohd Saleh Jaafar ◽  
Farah Nora Aznieta Abd. Aziz

Small concrete cover to dowel’s diameter reduces the cyclic performance of precast concrete frame with pinned dowel beam-column connection due to brittle concrete splitting failure around the dowel joint. Besides, utilisation of bearing pad thicker than half of dowel’s diameter causes the dowel bar to sustain greater tensile stress and plastic elongation up to their breaking point due to larger inclination of the dowel bar, particularly under the action of cyclic loading. Hence, a new precast beam-column joint with hook-end configuration and utilizing the advantage of high damping rubber (HDR), was proposed as the alternative for precast structures. Therefore, this study presented the horizontal and vertical cyclic performances of the precast frames with the proposed joint, through numerical analysis using finite element software. The numerical results were compared with a numerical modelled single pinned dowel connected precast frame, which was verified with the experimental results under horizontal cyclic loading. In terms of accumulative energy dissipation capacity, the numerical results showed that precast frames with the proposed joint demonstrated approximately 230% and 120% of improvement at 40 mm of horizontal cyclic level and 7 mm of vertical cyclic level, respectively, than the precast frame with single pinned dowel connection. It indicates that the viscoelastic behavior of HDR has contributed the benefit in this improvement.


2014 ◽  
Vol 580-583 ◽  
pp. 2134-2140
Author(s):  
Jian Zhang ◽  
Jian Feng Zhai ◽  
Xian Mei Wang ◽  
Jie Chen

Two-Dimensional finite element analysis was used to investigate the performance of seawall construction over weak subgrade soil using artificial base layer material consisted of cemented sand cushion comprising geosynthetics materials. Two types of base layer materials pure sand and cemented sand comprising husk rich ash and two types of geosynthetics materials geogrid and geotextile were used. Constitutive models were used to represent different materials in numerical analysis. The competence of two-dimensional numerical analysis was compared with experimental results. Numerical results showed a superior harmony with the experimental results. Finite element analysis model proved to be a great tool to determine the parameters that are difficult to measure in laboratory experiments. In addition, finite element analysis has the benefit of cost and time saving when compared to experimental investigation work. Numerical results showed strain induced in geosynthetics eliminated beyond a distance approximately equal six times of footing width.


2013 ◽  
Vol 29 (1_suppl) ◽  
pp. 315-338 ◽  
Author(s):  
Kazuhiko Kawashima ◽  
Ian Buckle

Including minor nonstructural damage, over 1,500 highway bridges and numerous rail bridges were damaged during the Tohoku-oki earthquake of 11 March 2011. The causes of this damage can be broadly classified in two categories: ground shaking, including ground failure (liquefaction); and tsunami inundation. Damage included span unseating, column shear and flexural failures, approach fill erosion, liquefaction induced settlement, and failed steel and elastomeric bearings. Since many bridges in the north Miyagi-ken and south Iwate-ken suffered extensive damage during the 1978 Miyagi-ken-oki earthquake, bridge performance during the 2011 earthquake is of particular interest. Advances in design and retrofit may be assessed by looking at the performance of bridges designed to post-1990 codes and those retrofitted since the Kobe earthquake in 1995. In both categories, bridge damage due to ground shaking was minor, thus validating the provisions in the post-1990 codes and the Japan bridge retrofit program. Damage that did occur due to ground shaking was mainly to bridges not yet retrofitted or only partly so. Tsunami-related damage included complete loss of span and erosion of backfills. However, many bridges survived, despite being totally submerged, and their performance gives insight into the potential design of tsunami-resistant bridges.


Author(s):  
Chang-New Chen

Development of differential quadrature related generalized methods, discrete element analysis methods and EDQ based time integration methods has been carried out the last few years. The related numerical algorithms are summarized and presented. Numerical results are also presented.


Sign in / Sign up

Export Citation Format

Share Document