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Application of consistent geometric decomposition theorem to dynamic finite element of 3D composite beam based on experimental and numerical analyses

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Frontiers of Structural and Civil Engineering 2020年第3期14卷 675-689页

作者： Iman FATTAHI Hamid Reza mirdamadi Hamid ABDOLLAHI Department of Mechanical Engineering Isfahan University of TechnologyIsfahan ***Iran

Analyzing static and dynamic problems including composite structures has been of high significance in research efforts and industrial *** this article,equivalent single layer approach is utilized for dynamic finite element procedures of 3D composite beam as the building block of numerous composite *** this model,both displacement and strain fields are decomposed into cross-sectional and longitudinal components,called consistent geometric decomposition ***,the model is discretized using finite clement *** local coordinate systems and a global one are defined to decouple mechanical degrees of ***,from the viewpoint of consistent geometric decomposition theorem,the transformation and element mass matrices for those systems are introduced here for the first *** same decomposition idea can be used for developing element stiffiness ***,comprehensive validations are conducted for the theory against experimental and numerical results in two case studies and for various conditions.

关键词： composite beam dynamic finite element degrees of freedom coupling experimental validation numerical validation

Optimizing and slope determination of final wall for Maiduk Mine with consideration of destabilizer factors

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矿业科学技术学报：英文版 2016年第3期26卷 501-509页

作者： shamsoddin Saeed Masoud Maarefvand Parviz Yaaghubi Ebrahim Geotechnical Engineer Mahyar Haffar Karmania Company Department Mining & Metallurgy Amirkabir University of Technology

In this research, determination of final slope for Maiduk copper mine of Kerman is investigated according to destabilizing factors of the mine. The development of the Maiduk Mine caused the extension of the mine area and also withdrawal of its wall. So, optimizing possibility of mine slope is essential. Finally,the magnitude of optimized slopes for different walls of the mine in association with executive commands with better factors of safety is provided. The results show that the most important destabilizer factors are the presence of water and pore pressure in the faults and the main joints. With the omission of pore pressure, mine wall for the designed depth is quite stable. This requires a drainage pattern in the lifetime of the mine. In an optimistic point of view, the minimum factor of safety of the wall will be 2.81 even without drainage. This conclusion allows optimizing the slope to its maximum magnitude of 51 degree. With the pessimistic engineering judgment and with the higher SF, the magnitude of the slope is optimized to 47 degree.

关键词：稳定因素最终边坡优化孔隙水压力矿山开发矿山边坡孔隙压力设计深度

In-vitro assessments of micro arc oxidized ceramic flms on AZ31 magnesium implant: Degradation and cell-surface response

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Progress in Natural Science:Materials International 2013年第4期23卷 425-433页

作者： A.Seyfoori Sh.mirdamadi M.Mehrjoo A.Khavandi School of Metallurgy and Materials Engineering Iran University of Science and Technology National Cell Bank Pasteur Institute of Iran

In this research,phosphate and silicate based ceramic flms were synthesized via micro arc oxidation(MAO) method on the surface of the magnesium *** the aim of orthopedic application of these coatings,corrosion behavior of them was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy in simulated body fuid(SBF) *** results indicated better corrosion resistance of the phosphate flm compared to the silicate ***,based on immersion tests,less pH and weight changes were obtained for the phosphate ***(G292) Cell response of the coated specimens showed better cell morphology on the surface of the phosphate flm than silicate flm after 6 and 24 h of *** was related to the more surface roughness and less degradation rate of the phosphate flm compared with silicate coating.

关键词： Corrosion Magnesium G292 cell Micro arc oxidation

Effect of Sulfur Precursor on Dimensions of One-dimensional CdS Nanocrystals

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Journal of Materials Science & Technology 2009年第4期25卷 462-464页

作者： M.Maleki Sh.mirdamadi R.Ghasemzadeh M.Sasani Ghamsari Department of Metallurgy and Material Engineering Iran University of Science & Technology Solid State Lasers Research Group Laser & Optics Research School

One-dimensional CdS nanocrystals have been prepared by solvothermal method using cadmium acetate as a cadmium precursor, elemental sulfur and Na2S, as a sulfur precursor, and ethylenediamine as a solvent at 150℃ for 5 h. The nanocrystals were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM） and UV-Vis absorption spectroscopy. XRD patterns indicate that both Na2S and elemental sulfur as the sulfur precursor result in CdS nanorods with wutzite phase （hexagonal structure）. SEM and TEM images show that diameter of CdS nanorods can be decreased using Na2S instead of elemental sulfur. For the growth of CdS nanorods, a mechanism has been proposed. Uv-Vis absorption of CdS nanorods （sulfur precursor： Na2S） was shown blue shift to 485 nm due to the quantum size effect.

关键词： Nanomaterials Semiconductors CdS nanorods Na2S Solvothermal method

Growth of TiO_2 Nanorods by Sol-gel Template Process

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Journal of Materials Science & Technology 2007年第5期23卷 611-613页

作者： A.Sadeghzadeh Attar Sh.mirdamadi F.Hajiesmaeilbaigi M.Sasani Ghamsari Department of Metallurgy and Materials Engineering Iran University of Science and TechnologyTehranIran Solid State Laser Research Group Laser Research Center11365-8486TehranIran

In this work, TiO2 nanorods with uniform diameter of about 100 nm and a length of several micrometers were successfully prepared by the sol-gel template method. Also the influence of molar ratios of precursor on the morphology and structure of TiO2 nanorods has been investigated. The prepared samples were characterized by Fourier transform infrared spectroscopy （FTIR）, X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The XRD results indicated that the TiO2 nanorods were crystallized in the anatase and rutile phases, after annealing to 400-700℃ up to 2 h.

关键词： TiO2 nanorods Sol-gel process Template-based growth

脉冲电沉积涂覆纳米羟基磷灰石的多孔Mg-Zn支架材料的体外生物降解能力和生物相容性(英文)

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Transactions of Nonferrous Metals Society of China 2015年第12期25卷 4018-4027页

作者： Z.S.SEYEDRAOUFI Sh.mirdamadi School of Metallurgy and Materials Engineering Iran University of Science and Technology

研究纳米羟基磷灰石(HAP)涂覆的多孔Mg-2Zn(质量分数,%)支架材料的生物降解能力和生物相容性。采用脉冲电沉积制备羟基磷灰石涂层。对涂覆HAP的支架在碱性溶液中进行后处理来改善其生物降解性和生物相容性。研究支架和HAP涂层的显微组... 详细信息

研究纳米羟基磷灰石(HAP)涂覆的多孔Mg-2Zn(质量分数,%)支架材料的生物降解能力和生物相容性。采用脉冲电沉积制备羟基磷灰石涂层。对涂覆HAP的支架在碱性溶液中进行后处理来改善其生物降解性和生物相容性。研究支架和HAP涂层的显微组织和成分以及它们在模拟体液(SBF)中的降解和细胞毒性。经过碱溶液处理后的涂层由几乎垂直于基体的直径小于100 nm的针状HAP组成,具有和天然骨头相似的成分,浸泡在SBF中后,产物为HAP、(Ca,Mg)3(PO4)2和Mg(OH)2。涂覆HAP和经过处理碱处理后的支架比未涂覆HAP的支架具有更高的生物相容性和细胞存活性。MG63细胞粘附在涂覆HAP和经过碱处理后的支架的表面并增殖,使这些支架有望应用于医学。结果表明:纳米HAP的脉冲电沉积和碱处理可有效改善多孔Mg-Zn支架的生物降解能力和生物相容性。

关键词：多孔Mg-Zn支架羟基磷灰石涂层脉冲电沉积生物降解能力生物相容性

高分散多壁碳纳米管增强铝基复合材料的制备(英文)

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新型炭材料 2012年第3期27卷 161-165页

作者： A. H. Javadi Sh. mirdamadi M. A. Faghihisani S. Shakhesi R. Soltani Department of Materials Engineering Science and Research Branch Islamic Azad University Tehran Iran Engineering Research Institute Tehran Iran

采用机械合金化技术制备高分散多壁碳纳米管(MWCNTs)-铝(Al)复合材料。将纯度99%的铝粉和质量分数2%的MWCNTs经超声和水平球磨处理使Al颗粒与MWCNTs间产生机械键合力。场发射SEM观察表明,MWCNTs分散在Al薄片的表面,随球磨时间的不同,颗... 详细信息

采用机械合金化技术制备高分散多壁碳纳米管(MWCNTs)-铝(Al)复合材料。将纯度99%的铝粉和质量分数2%的MWCNTs经超声和水平球磨处理使Al颗粒与MWCNTs间产生机械键合力。场发射SEM观察表明,MWCNTs分散在Al薄片的表面,随球磨时间的不同,颗粒大小和形貌各异。采用加压烧结手段将混合粉末加工成块体材料,其微观硬度测试表明,加入MWCNTs后Al基体的机械性能得到提高。

关键词：多壁碳纳米管金属基体复合材料球磨