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Progressive Collapse Analysis of an FPSO Vessel Hull Girder Under Vertical Bending Considering Different Corrosion Models

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Journal of Marine Science and Application 2020年第4期19卷 674-692页

作者： Zorareh Nouri mohammad reza khedmati Department of Maritime Engineering Amirkabir University of Technology(Tehran Polytechnic)Tehran 15916-34311Iran

Nowadays,with the increasing operational life of ships,the aging effects on their structural behavior need to be investigated *** the corrosive marine environment taken into consideration,one of the important effects of aging that must be studied is thickness *** this paper,with the use of previously proposed equivalent thickness formulations for corroded plates,the progressive collapse analysis software HULLST is enhanced,and then,the effects of different corrosion models of uniform,random,pitting,and tanker pattern types on the ultimate and residual strengths of a floating production,storage,and offloading vessel hull girder are evaluated for the ages of 0 to 25 *** reveal that the uniform corrosion and random corrosion models have close *** value of relative reduction in the ultimate strength of ship hull girder(compared with the intact condition)ranges roughly from 6%for the age of 5 years to 17%for the age of 25 years in the hogging *** relative reduction in the ultimate strength ranges from 4%to 16%in the sagging *** corrosion and tanker pattern(random)corrosion models lead to higher relative reductions in ultimate *** pitting corrosion model leads to a 16%–32%relative reduction in the ultimate strength for the ages of 5–25 years of the ship in either hogging or *** tanker pattern(random)corrosion model leads to a 6%–37%relative reduction in the ultimate strength in the hogging mode and 3%–31%in the sagging mode at ship ages of 5 to 25 years.

关键词： Uniform corrosion Random corrosion Pitting corrosion Tanker pattern corrosion Progressive collapse analysis Vertical bending Ultimate strength Residual strength

Temperature-jump tensile tests to induce optimized TRIP/TWIP effect in a metastable austenitic stainless steel

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International Journal of Minerals,Metallurgy and Materials 2024年第9期31卷 2025-2036页

作者： mohammad Javad Sohrabi Hamed Mirzadeh Saeed Sadeghpour Abdol reza Geranmayeh reza Mahmudi School of Metallurgy and Materials Engineering College of EngineeringUniversity of Tehran14395-515TehranIran Centre for Advanced Steels Research Materials and Mechanical EngineeringUniversity of Oulu90014 OuluFinland

In the present work,plastic deformation mechanisms were initially tailored by adjusting the deformation temperature in the range of 0 to 200℃ in AISI 304L austenitic stainless steel,aiming to optimize the strength-ductility *** was shown that the combined twinning-induced plasticity(TWIP)/transformation-induced plasticity(TRIP)effects and a wider strain range for the TRIP effect up to higher strains by adjusting the deformation temperature are good strategies to improve the strength-ductility synergy of this metastable stainless *** this regard,by consideration of the observed temperature-dependency of plastic deformation,the controlled sequence of TWIP and TRIP effects for archiving superior strength-ductility trade-off was intended by the pre-designed temperature jump tensile ***,the optimum tensile toughness of 846 MJ/m^(3) and total elongation to 133% were obtained by this strategy via exploiting the advantages of the TWIP effect at 100℃ and the TRIP effect at 25℃ at the later stages of the ***,a deformation-temperature-transformation(DTT)diagram was developed for this metastable ***,based on work-hardening analysis,it was found that the main phenomenon constraining further improvement in the ductility and strengthening was the yielding of the deformation-induced α′-martensite.

关键词： metastable stainless steels transformation-induced plasticity twinning-induced plasticity stacking fault energy mechanical properties

Movement Trend Alterations in the Periaqueductal Gray(PAG)-Employed Ratbot Navigation Are Correlated with Stimulation Parameters

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Journal of Bionic Engineering 2024年第2期21卷 866-876页

作者： Sina Khajei Abed Khorasani mohammad reza Afarinesh Vahid Sheibani Neuroscience Research Center Institute of NeuropharmacologyKerman University of Medical SciencesKerman***Iran Cognitive Neuroscience Research Center Institute of NeuropharmacologyKerman University of Medical SciencesKerman***Iran

In previous studies,Periaqueductal Gray(PAG)stimulation was used to stop ratbots from *** to the homology between the PAG and the intercollicular nucleus,which has been used for forward movement in birds,we investigated the possibility of PAG application to induce forward locomotion for the first *** a corridor maze,the traveled distances via PAG electrical stimulation were examined in nine Wistar male rats during three sessions.A custom-designed stimulator was developed to apply the *** results showed reductions in responses to stimulation over ***,the traveled distances had negative slopes during the consecutive trials(in 8 out of the 9 rats),and the slope mean was significantly different from *** was a strong correlation between the stimulation parameters(electric Charge per Phase(CPP)and the Number of Pulses(NP))and the observed *** negative Movement Slopes(MS)were highly correlated with the CPP and the NP,as the Pearson's linear correlation coefficients were−0.87 and−0.79,*** MS-CPP coefficients of determination(R-squared)were also between 0.76 and *** addition,the MS-NP coefficients of determination were between 0.63 and ***,it is concluded that the electrical stimulation parameters influence the behavioral outcomes ***,the PAG area may be considered a suitable candidate for forward locomotion control in the future if the area is harnessed effectively to prevent undesirable chaotic behaviors.

关键词： Periaqueductal Gray(PAG) Navigation Ratbot Animal-robot Forward locomotion Movement slope

平面内压力和侧向压力组合作用下预测连续加劲铝板极限强度的经验公式

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钢结构(中英文) 2010年第3期 88-89页

作者： mohammad reza khedmati mohammad reza Zareei Philippe Rigo

在对连续加劲铝板屈曲和极限强度的敏感性研究基础之上,对压力作用下的铝板进行了深入研究。开发了一个经验公式,用于预测海洋工程中采用焊接加劲铝板在平面内轴压和各种侧向压力作用下的极限抗压强度。极限抗压强度的计算利用了一些的... 详细信息

在对连续加劲铝板屈曲和极限强度的敏感性研究基础之上,对压力作用下的铝板进行了深入研究。开发了一个经验公式,用于预测海洋工程中采用焊接加劲铝板在平面内轴压和各种侧向压力作用下的极限抗压强度。极限抗压强度的计算利用了一些的铝板敏感性分析的相关数据,推导出来的公式中含有两个参数,分别是板长细比和柱(加劲肋)长细比。推导过程中也用到了回归分析。公式考虑了焊接对初始缺陷和热影响区的影响。

关键词：极限强度连续加劲铝板轴向受压侧向受压经验公式热影响区有限元法回归分析

Interplay between temperature-dependent strengthening mechanisms and mechanical stability in high-performance austenitic stainless steels

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International Journal of Minerals,Metallurgy and Materials 2024年第10期31卷 2182-2188页

作者： mohammad Javad Sohrabi Hamed Mirzadeh Saeed Sadeghpour Milad Zolfipour Aghdam Abdol reza Geranmayeh reza Mahmudi School of Metallurgy and Materials Engineering College of EngineeringUniversity of Tehran14395-515 TehranIran Centre for Advanced Steels Research Materials and Mechanical EngineeringUniversity of Oulu90014 OuluFinland Department of Mechanical Engineering College of EngineeringUniversity of Tehran14395-515 TehranIran

The effects of deformation temperature on the transformation-induced plasticity(TRIP)-aided 304L,twinning-induced plasti-city(TWIP)-assisted 316L,and highly alloyed stable 904L austenitic stainless steels were compared for the first time to tune the mechan-ical properties,strengthening mechanisms,and strength-ductility *** this purpose,the scanning electron microscopy(SEM),electron backscattered diffraction(EBSD),X-ray diffraction(XRD),tensile testing,work-hardening analysis,and thermodynamics calcu-lations were *** induced plasticity effects led to a high temperature-dependency of work-hardening behavior in the 304L and 316L stainless *** the deformation temperature increased,the metastable 304L stainless steel showed the sequence of TRIP,TWIP,and weakening of the induced plasticity mechanism;while the disappearance of the TWIP effect in the 316L stainless steel was also ***,the solid-solution strengthening in the 904L superaustenitic stainless steel maintained the tensile properties over a wide temper-ature range,surpassing the performance of 304L and 316L stainless *** this regard,the dependency of the total elongation on the de-formation temperature was less pronounced for the 904L alloy due to the absence of additional plasticity *** results re-vealed the importance of solid-solution strengthening and the associated high friction stress for superior mechanical behavior over a wide temperature range.

关键词： austenitic stainless steels mechanical behavior stacking fault energy metastability mechanical twinning

平面内压力和侧向压力组合作用下连续加劲铝板弹性屈曲和极限强度的敏感性分析

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钢结构(中英文) 2009年第10期 80-81页

作者： mohammad reza khedmati mohammad reza Zareei Philippe Rigo

轴向挤压和不同量级的侧向压力作用下,运用非线性有限元法对高强铝合金加劲板进行后屈曲性能分析,并对研究结果进行了总结。分析中考虑了材料和几何非线性,几个关键的变量包括:板厚度;边界条件;加劲肋的几何特性,包括其几何缺陷;焊接中... 详细信息

轴向挤压和不同量级的侧向压力作用下,运用非线性有限元法对高强铝合金加劲板进行后屈曲性能分析,并对研究结果进行了总结。分析中考虑了材料和几何非线性,几个关键的变量包括:板厚度;边界条件;加劲肋的几何特性,包括其几何缺陷;焊接中产生的热效应区域宽度和残余应力。对这些变量对此类加劲板后屈曲性能和极限强度的影响进行了详细的研究。

关键词：屈曲荷载极限强度后屈曲性能连续加劲铝板轴向挤压侧向压力热效应区有限元法

Numerical investigation of supercontinuum generation and optical frequency combs in Si N-based PCF with high nonlinear coefficient

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Optoelectronics Letters 2024年第3期20卷 163-170页

作者： mohammad reza Alizadeh Mahmood Seifouri Saeed Olyaee Faculty of Electrical Engineering Shahid Rajaee Teacher Training UniversityTehranIran Nano-photonics and Optoelectronics Research Laboratory(NORLab) Shahid Rajaee Teacher Training UniversityTehranIran

In this paper, a photonic crystal fiber(PCF) with a dispersion-engineered and high nonlinear coefficient has been designed for supercontinuum generation(SCG) and frequency comb generation(FCG). The proposed PCF has a Si_(3)N_(4) rod in the core. This rod provides more optical confinement in the core by increasing the refractive index of the core. This high confinement reduces the effective mode area of PCF and thus increases the nonlinear coefficient.

关键词： optical fiber nonlinear

Multidisciplinary design optimization of a dual-spin guided vehicle

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Defence Technology（防务技术） 2024年第7期37卷 133-148页

作者： Jalal Karimi mohammad reza Rajabi Seyed Hossein Sadati Seyed Mahid Hosseini Department of Aerospace Engineering Malek Ashtar University of TechnologyTehranIran

In this research,a Multidisciplinary Design Optimization approach is proposed for the dual-spin guided flying projectile design considering external and internal parts of the body as design *** this way,a parametric formulation is *** related disciplines,including structure,aerodynamics,guidance,and control are *** total mass,maximum aerodynamic control effectiveness,minimum miss distance,maximum yield stress in all subsystems,controllability and gyroscopic stability constraints are some of objectives/constraints taken into *** problem is formulated in All-At-Ones Multidisciplinary Design Optimization approach structure and solved by Simulated Annealing and minimax *** optimal configurations are evaluated in various *** resulted optimal configurations have met all design objectives and constraints.

关键词： Flying projectile optimal design All-at-ones multidisciplinary optimization Structure discipline Guidance and control discipline Aerodynamic discipline

Bulk-boundary and RPS thermodynamics from topology perspective

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Chinese Physics C 2024年第9期48卷 244-253页

作者： Jafar Sadeghi mohammad reza Alipour Saeed Noori Gashti mohammad Ali S.Afshar Department of Physics Faculty of Basic SciencesUniversity of Mazandaran P.O.Box 47416-95447BabolsarIran School of Physics Damghan UniversityP.O.Box ***DamghanIran

In this study,we investigate the bulk-boundary and restricted phase space(RPS)thermodynamics of Rissner-Nordstrom(R-N)AdS and 6-dimensional charged Gauss-Bonnet AdS black ***,we examine the topological characteristics of the considered black holes and compare them with the results of extended *** determine that the topological behavior of the bulk-boundary thermodynamics is the same as that of the extended thermodynamics,whereas the RPS thermodynamics exhibits a distinct ***,we demonstrate that within the RPS formalism,there is only one critical point with a topological charge of+1(Q_(t)=+1).Moreover,in the RPS formalism,the inclusion of higher-derivative curvature terms in the form of GaussBonnet gravity does not alter the topological classification of critical points in charged AdS black holes.

关键词： bulk-boundary restricted phase space topological charge thermodynamics