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This paper has proposed a new perspective of studying internal structure-based tests, the results of which will improve the present experimental methods and enrich our understanding of rock structure-based modeling without any core preparations, with low cost in a short time. Pore volume compressibility (PVC) is an important feature of rock and is related to mechanical and structural behavior of porous rock sample. An accurate evaluation of pore volume compressibility depends on experimental test which is time-consuming and costly. This paper outlines new method for evaluation of PVC of rock cores using a computed tomography (CT) scan-based finite element method (FEM). The verification studies were performed on a series of porous rock cores which were extracted from deep oil reservoirs in Iran. In order to construct a finite element model, a relationship between spatial elastic properties of samples and CT-scanned data images was derived. The samples were scanned by a conic beam computed tomography (CBCT) machine, and the scanned data were converted into a model to simulate PVC tests. The pore volumetric strains were obtained from a linear elastic analysis for each stress and pore pressure step. To validate the finite element analysis (FEA) results, a series of experimental PVC tests were conducted on the pre-scanned samples and PVC curves were extracted. As a result, the predictions calculated from the CT scan-based numerical models have shown a good correlation with the results obtained from laboratory experiments. The results revealed that it is possible to simulate PVC tests using this numerical proposed evaluation method in such a way that the cost and time of the tests were lowered. [ABSTRACT FROM AUTHOR]

This paper addresses an integrated and developed approach to the design of an Axial Flux Permanent Magnet Wind Generator (AFPMWG). The proposed analytical method of design employs the size equations and precise inductance calculations simultaneously, as well as considering the mechanical constraints of the back-iron disc of the rotor. An Elitist Genetic Algorithm (EGA), such as a high capability optimization method, has been used to solve the equations and design of a wind generator with predefined rating power. The objectives of the coreless AFPMWG design process are minimizing the magnet consumption, maximizing machine efficiency, and achieving maximum sinusoidal induction voltage, considering the wind properties of the geographical area of utilization. The optimal calculation of the permanent magnet thickness is also taken into consideration in this work. The flux density distribution in all parts of the machine has been investigated for the magnetic saturation phenomenon. In this regard, special attention is paid to rotor back discs, which are made from nonlinear material with an optimum thickness. The inductance of the leakage flux of the coreless machine has been considered by parallel computation via the Finite Element Method (FEM) and analytical equations. Finally, three-dimensional and two-dimensional finite element analyses are used to validate the performance of the machine design according to the characteristics of Iran wind resources. The results show the high ability of the proposed approach in AFPMWG design and in considering the objectives and constraints carefully. [ABSTRACT FROM AUTHOR]

Soil-Structure Interaction (SSI) is an outstanding factor that influences the linear and nonlinear performance of any structure, and it can be taken into account as one of the most important and effective considerations on the seismic behavior of buildings. On the other hand, historic masonry buildings are specific and important structures, which are significantly affected by SSI. Preservation of these buildings is one of the main demands of every culture and every society; and evaluating the behavior of these buildings under natural events such as earthquake, considering aforementioned SSI phenomenon, is an essential step, in this regard. In this paper, the impact of SSI on the out-of-plane behavior of an ancient building in Iran, named Arge-Tabriz, has been investigated utilizing Finite Element Method (FEM). Modal and nonlinear Time-History (TH) analyses results revealed that SSI has a significant decreasing effect on the acceleration response due to removing the effective mode vectors from the resonance area of the acceleration response spectra. On the contrary, SSI has a remarkable increasing impact on the displacement response of Arg's walls according to the displacement response spectra. [ABSTRACT FROM AUTHOR]

Purpose – In writing this paper, the authors investigated the use of electromagnetic sensors in axle counter applications by means of train wheel detection. The purpose of this paper is to improve the detection capability of train wheel detectors, by installing them in the optimal orientation and position, using finite element modeling (FEM) in combination with metamodeling techniques. The authors compare three common metamodeling techniques for the special case of wheel detector orientation: response surface methodology; multivariate adaptive regression splines; and kriging. Design/methodology/approach – After analyzing the effective parameters of a train wheel detector, an appropriate method for decreasing the system susceptibility to electromagnetic noises is presented. Findings – The results were validated using a laboratory-based system and also the results of field tests carried out on the Iranian railway network. The results of the study suggest that the FEM method and a metamodeling technique can reduce the computational efforts and processing time. Originality/value – In this paper, combination of FEM and metamodeling approaches are used to optimize the railway axle counter coils orientation, which is more insusceptible to electromagnetic noise than initial arrangement used by some signallers. [ABSTRACT FROM AUTHOR]

Purpose - The purpose of the paper is to present a new method of controlling through susceptible slopes in order to reduce the risk of landslides. Design/methodology/approach - Geotechnical and geological characteristics were collected and different FEM analyses were carried out in a case study of the Alasht valley in Northern Iran in order to determine susceptibility to landslides and consider appropriate countermeasures. Gravel drain piles have a real feel of reducing the pore water pressure in times of seismic loading, so they are used as a remediation method. The results clearly show their effects and an increase in safety as a result. Findings - Since the water table situation has a significant effect on stability, the present study focused on an example of using a seepage controlling system and its effect on the safety factor for different slopes in the area of Alasht, Northern Iran. Several FEM analyses were carried out on a landslide susceptible case. The results from FEM analysis of different slopes in the study area show a high susceptibility to landslides for six sites. Installing a gravel drain pile surrounded by a non-woven geotextile layer leads to an increase in the safety factor against landslides. As a result, after installing gravel drain piles in the upper parts of slopes in order to control run out and ground water rising up in times of heavy rainfall, the safety factor against landslides in both static and seismic loading improved significantly. Originality/value - The literature regarding controlling seepage in order to reduce the risk of landslides is limited. This paper collects and analyses geotechnical and geological data from the Alasht valley as an example to show the high risk of susceptibility to landslides. [ABSTRACT FROM AUTHOR]

In this paper the slope stability of Aydoghmoosh earth dam situated in the north west of Iran is evaluated by various methods of limit equilibrium, finite element and finite difference. Among numerous limit equilibrium methods, Simplified Bishop, Janbu and Spencer are selected so that cover a wide range from simplest to most complicated. The results of all methods are compared together and advantages/disadvantages of them are also discussed. [ABSTRACT FROM AUTHOR]

• None of the studied existing and parametric domes fails due to the earthquake. • The induced tensile stress to the tensile strength ratio increases by increasing the span. • The geometrical shape of the dome has a great effect on structural behaviour. • In general, a single-shell dome is stiffer than a double-shell dome and experiences smaller stresses. Despite the fact that Iran is an earthquake prone country and most of its historical buildings are made of brick masonry that is weak in tension, a large number of domical buildings have been constructed all over the country since many centuries ago. Most of magnificent domes in Iran have survived severe earthquakes. The discontinuous double-shell dome has been widely used for important buildings such as mosques and churches. This type of dome provides the possibility of constructing high and large spaces in order to show magnificence and also accommodate a large number of people inside. In this paper, the structural performance of Persian brick masonry discontinuous double-shell domes against earthquakes has been studied. Different shapes of upper and lower shells have been studied. The domes have had spans of 12 m, 15 m and 18 m and a decreasing thickness from the base to the apex with an optimum apex to base thickness ratio. Domes have been analysed under earthquake load by the non-linear finite element method. The Willam-Warnke failure criterion has been used for brick masonry materials. In addition to parametric study, two existing discontinuous double-shell domes of the Imam mosque and Bedkhem church, and two existing single-shell domes of the Saint Mary church and Saint Stepanos monastery in Isfahan have been studied. The values of maximum stresses have been obtained for these domes. Obtained results indicate that selected earthquakes do not cause the failure of the studied domes. The induced stresses increase by increasing the span. The performance of domes is dependent on the geometrical shape of the upper and lower shells. The dome with a drop four-centred upper shell and a drop elliptical lower shell has the best structural behaviour. [ABSTRACT FROM AUTHOR]

• CLT panels were manufactured from poplar as a fast-growing and hand-planted species. • CLTs were tested under out-of-plane loading in various span-to-depth ratios. • Mechanical properties of CLTs were computed and predicted based on experimental and analytical methods. • Finite element method (FEM) could predict the amount and locations of bending stresses and crack initiation. With the expansion of cross-laminated timber (CLT) material throughout the global construction community, an effort is being made to explore the use of regionally produced CLT materials from Iran, including the testing of fast-grown, hand-planted poplar (Populus alba). This paper investigated the out-of-plane bending properties of CLT panels manufactured using poplar at various span-to-depth ratios (SDR). Mechanical properties of poplar CLTs investigated included the modulus of rupture, apparent modulus of elasticity, effective bending stiffness, effective shear stiffness, and maximum shear stress in both the major and minor directions. Experimental test results were compared with both the shear analogy model and finite element method (FEM) results to examine the use of predictive modeling. Bending properties were predicted using the shear analogy method and FEM compared well with experimental results, with the FEM able to predict the distribution of bending and shear stress across the beam thickness. Modulus of rupture and apparent modulus of elasticity increased with increasing SDR in both the major and minor strength directions. In the major strength direction, the effective modulus of elasticity and maximum shear strength values predicted by the shear analogy method were in good agreement with experimental results. As noted in previous studies, the effective shear stiffness predicted by the shear analogy method in the major strength direction was 510% less than that of experimental results. [ABSTRACT FROM AUTHOR]