1,721,032 research outputs found
Two-step advanced numerical approach for the design of low-cost unbonded fiber reinforced elastomeric seismic isolation systems in new masonry buildings
No full textIn developing countries, masonry is generally employed in the construction of residential buildings due to its relatively cheap cost. However, these structures are often provided with inadequate seismic protection. A low-cost base isolation aimed at decreasing the seismic vulnerability of masonry buildings is studied in this work from a numerical standpoint. The studied isolator is an unbonded fiber-reinforced elastomeric isolator (UFREI). With fewer rubber pads than conventional isolators, the UFREI is a cheaper option. A 3D finite element analysis is performed to predict the behavior of the UFREI under large displacements. The isolation system is then implemented into a two-story masonry building prototype, where the 3D model of a single UFREI is substituted by a nonlinear spring and a damper. This simplification decreases the computational costs of the analysis. Seven scaled ground motions are applied to the numerical model to investigate the seismic performance of the isolated masonry building subjected to a maximum considered earthquake. Nonlinear dynamic analyses are performed in Abaqus, taking into account the two horizontal components of the seismic motion. Numerical results show an excellent isolation performance of the system, with a significant reduction of the inter-story drift and a suitable deformation of the UFREIs, as well as demonstrate that the simplified numerical approach adopted is useful for practical design and quick safety assessments
Practical designs and seismic performances of residential masonry building isolated with fiber reinforced elastomeric isolators
No full textSince the seismic performance of masonry is considerably low, the masonry structure is not recommended for regions with high seismic risks. However, it is so far the preferred structure for low-class housing, particularly in developing countries. Comprehensive numerical and experimental studies are carried out to evaluate the possibility to build low-rise masonry housing with a suitable isolation system. Low-cost seismic rubber isolators reinforced with fiber are examined to product an innovative isolation device. To reduce the cost, rubber materials considered are recycled compounds derived from manufacturing waste. The utilization of fiber instead of steel can reduce the weight and allows the engineer to implement unbonded application of base isolators. Some technological details for masonry building are proposed to assure that the isolation system works well. In order to evaluate the seismic performance of such isolation system, non-linear static and dynamic analyses are performed through numerical models in a commercial finite element code. The results indicate excellent performances of low-cost isolation system so that this innovative residential masonry building is feasible for real application particularly in developing countries
A low cost rubber seismic isolation system for new masonry residential buildings in developing countries
No full textRubber isolators are used widely in constructions which require a vibration or seismic isolation. It consists of rubber layers and reinforcements that can be steel or fiber lamina. The fiber reinforced isolator results in a lower cost of production and
application than that of steel. Using fiber reinforced isolator allows us to make an unbonded model of rubber bearing. This model leads to a smaller horizontal stiffness and larger displacement of isolators. Researchers consider the Unbonded Fiber Reinforced Elastomeric Isolator (U-FREI) as a low-cost form of rubber bearings. U-FREIs are suitable to isolate seismically a masonry building, which is a common type of housing in developing countries. In this work, we present a finite element model (FEM) to predict the behavior of the U-FREIs undergoing moderate deformations. We adopt a Yeoh hyperelasticity model which is available in the standard package of Abaqus FE software and estimate its coefficients through the available experimental data. Then, we apply tha isolation system onto masonry housing with some simplified methods. We also observe the horizontal behaviors of U-FREIs under different vertical loads and consider a critical condition when the isolators start to be unstable. In parallel, we perform an analytical model to predict the shear behavior and the deformation limit of isolators. Finally, the results show that the analytical model is sufficiently accurate compared to the FE analyses
Low cost rubber seismic isolation of residential new masonry buildings in developing countries
Full text linkA Finite element model was established to examine performance of a low-cost friction base-isolation system in reducing seismic vulnerability of rural buildings. This study adopts an experimental investigation of the isolation system which was conducted in India. Four friction isolation interfaces, namely, marble-marble, marble-high-density polyethylene, marble-rubber sheet, and marble-geosynthetic were involved. Those interfaces differ in static and dynamic friction coefficient obtained through previous research. The FE model was performed based on a macroscopic approach and the masonry wall is assumed as an isotropic element. In order to observe structural response of the masonry house, elastic and plastic parameters of the brick wall were studied. Concrete damage plasticity (CDP) model was adopted to determine non-linear behavior of the brick wall. The results of FE model shows that involving these friction isolation systems could much decrease response acceleration at roof level. It was found that systems with marble-marble and marble-geosynthetic interfaces reduce the roof acceleration up to 50% comparing to the system without isolation. Another interesting result is there was no damage appearing in systems with friction isolation during the test. Meanwhile a severe failure was clearly visible for a system without isolation
Inovasi Sambungan Mekanis Menggunakan Clamp Baja Untuk Tulangan Beton
Full text linkPertumbuhan perkotaan di Indonesia beberapa waktu terkakhir cenderung lebih mengarah pada overground space. Hal ini disebabkan karena populasi penduduk perkotaan mengalami peningkatan yang signifikan dan tidak sebanding dengan lahan yang tersedia. Banyaknya bangunan tinggi dan gedung pencakar langit juga menandai fenomena tersebut. Namun, bangunan tinggi dan gedung pencakar langit memiliki potensi terhadap bahaya gempa bumi, lebih lagi Indonesia adalah termasuk wilayah yang rawan terjadi gempa bumi. Dalam perencanaan bangunan tahan gempa dua hal pokok yang perlu diperhatikan adalah kekuatan dan daktilitas. Kemampuan berdeformasi dan kekuatan pada sambungan antar tulangan menjadi pertimbangan dalam desain struktur tahan gempa. Dari hasil pengujian tarik clamp baja untuk sambungan mekanik tulangan D13 diperoleh yield strength 270.69 Mpa, ultimate tensile strength 351.45 Mpa dan beban maksimum 4757 kg serta elongation 40%. Sedangkan untuk sambungan mekanik tulangan D16 diperoleh yield strength 217.80 Mpa, ultimate tensile strength 327.605 Mpa dan beban maksimum 6717 kg serta elongation 32%. Pada penelitian ini digunakan 2 (dua) buah clamp baja. Namun, untuk memeperoleh hasil yang lebih baik perlu penambahan jumlah clamp dan peningkatan kualitas material clamp baja
A REGIONAL REFINEMENT FOR FINITE ELEMENT MESH DESIGN USING COLLAPSIBLE ELEMENT
No full textA practical algorithm for automated mesh design in finite element analysis is developed. A regional mixed mesh improvement procedure is introduced. The error control%2C algorithm implementation%2C code development%2C and the solution accuracy are discussed. Numerical example includes automated mesh designs for plane elastic media with singularities. The efficiency of the procedure is demonstrated. Abstract in Bahasa Indonesia : regional+refinement%2C+mesh+generation%2C+isoparametric+element%2C+collapsible+elemen
A REGIONAL REFINEMENT FOR FINITE ELEMENT MESH DESIGN USING COLLAPSIBLE ELEMENT
No full textA practical algorithm for automated mesh design in finite element analysis is developed. A regional mixed mesh improvement procedure is introduced. The error control%2C algorithm implementation%2C code development%2C and the solution accuracy are discussed. Numerical example includes automated mesh designs for plane elastic media with singularities. The efficiency of the procedure is demonstrated. Abstract in Bahasa Indonesia : regional+refinement%2C+mesh+generation%2C+isoparametric+element%2C+collapsible+elemen
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