Journal of Engineering Science最新文献_第9页

Effect of Transverse Base Width Restraint on the Cracking Behavior of Massive Concrete 横向基宽约束对大体积混凝土开裂性能的影响

Journal of Engineering Science Pub Date : 2023-07-22 DOI: 10.31026/j.eng.2012.11.02

A. Ali, O. F. Al-Damluji, A. H. Al-Zuhairi

{"title":"Effect of Transverse Base Width Restraint on the Cracking Behavior of Massive Concrete","authors":"A. Ali, O. F. Al-Damluji, A. H. Al-Zuhairi","doi":"10.31026/j.eng.2012.11.02","DOIUrl":"https://doi.org/10.31026/j.eng.2012.11.02","url":null,"abstract":"The effect of considering the third dimension in mass concrete members on its cracking behavior is investigated in this study. The investigation includes thermal and structural analyses of mass concrete structures. From thermal analysis, the actual temperature distribution throughout the mass concrete body was obtained due to the generation of heat as a result of cement hydration in addition to the ambient circumstances. This was performed via solving the differential equations of heat conduction and convection using the finite element method. The finite element method was also implemented in the structural analysis adopting the concept of initial strain problem. Drying shrinkage volume changes were calculated using the procedure suggested by ACI Committee 209 and inverted to equivalent temperature differences to be added algebraically to the temperature differences obtained from thermal analysis. Willam-Warnke model with five strength parameters is used in modeling of concrete material in which cracking and crushing behavior of concrete can be included. The ANSYS program was employed in a modified manner to perform the above analyses. A thick concrete slab of 1.5m in thickness and 10m in length was analyzed for different widths 2, 4, 8, and 10m to produce different aspect ratios (B/L) of 0.2, 0.4, 0.8, and 1.0 respectively. The results of the analyses show an increase in cracking tendency of mass concrete member as the aspect ratio of the same member is increased due to the effect of transverse base restraint. Accordingly, such effect cannot be ignored in the analysis of base restrained mass concrete structures subjected to temperature and drying shrinkage volume changes.","PeriodicalId":52570,"journal":{"name":"Journal of Engineering Science","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76907883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigation Parameters of Resistance Spot Welding For AA1050 Aluminum Alloy Sheets AA1050铝合金薄板电阻点焊工艺参数研究

Journal of Engineering Science Pub Date : 2023-07-22 DOI: 10.31026/j.eng.2012.10.04

K. M. Daws, Hammed Al-Saadi, Ihsan Kadhom, A. Al-Naimi

{"title":"Investigation Parameters of Resistance Spot Welding For AA1050 Aluminum Alloy Sheets","authors":"K. M. Daws, Hammed Al-Saadi, Ihsan Kadhom, A. Al-Naimi","doi":"10.31026/j.eng.2012.10.04","DOIUrl":"https://doi.org/10.31026/j.eng.2012.10.04","url":null,"abstract":"The parameters of resistance spot welding (RSW) performed on low strength commercial aluminum sheets are investigated experimentally, the performance requirements and weldability issues were driven the choice of a specific aluminum alloy that was AA1050. RSW aluminum alloys has a major problem of inconsistent quality from weld to weld comparing with welding steel alloys sheet, due to the higher thermal conductivity, higher thermal expansion, narrow plastic temperature range, and lower electrical resistivity. Much effort has been devoted to the study of describing the relation between the parameters of the process (welding current, welding time, and electrode force) and weld strength. Shear-tensile strength tests were performed to indicate the weld quality. A weld lobe diagrams were constructed to evaluate the weldability of three sheet thicknesses of this alloy. Most appropriate welding time and electrode force are 5 cycles and 1.75- 2.25 kN respectively. The ranges of the weldability are 14-28, 18-30, and 22-32 kA for 0.6, 1.0, and 1.5 mm sheet thicknesses respectively. A statistical regression analysis was used to demonstrate the relationship of the process parameters and the strength of the weldments. Two empirical equations for each thickness were proposed to estimate the shear tensile strength of the weldments, one for quadratic and the other linear relationship between the process parameters and the strength. There are no significant differences between the equations when applied to the available data.","PeriodicalId":52570,"journal":{"name":"Journal of Engineering Science","volume":"111 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79282266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of Steel Fibers on the Properties of Refractory Free Cement Concrete 钢纤维对无耐火水泥混凝土性能的影响

Journal of Engineering Science Pub Date : 2023-07-22 DOI: 10.31026/j.eng.2012.10.06

A. A. Salih, H. A. Mohammed

引用次数: 2

The Characteristics of the Traditional Urban Configuration of ArabIslamic Cities through Form and Moral Values: Al-Kadhimiya as a Case Study 从形式与道德价值看阿拉伯伊斯兰城市的传统城市形态特征——以Al-Kadhimiya为例

Journal of Engineering Science Pub Date : 2023-07-22 DOI: 10.31026/j.eng.2012.10.09

S. J. Al-Khafaji, Sahar B. Mahmood Al-Qaisi

{"title":"The Characteristics of the Traditional Urban Configuration of ArabIslamic Cities through Form and Moral Values: Al-Kadhimiya as a Case Study","authors":"S. J. Al-Khafaji, Sahar B. Mahmood Al-Qaisi","doi":"10.31026/j.eng.2012.10.09","DOIUrl":"https://doi.org/10.31026/j.eng.2012.10.09","url":null,"abstract":"This paper studies the main characteristics of the traditional urban configuration of Arab cities, as an important built heritage, discussing the approach adopted with such configuration at the local level, and examines its ability to preserve the character of the city, as well as, its responsiveness to the recent requirements of its society that constantly change; in order to reach the appropriate procedures to deal with the traditional urban configuration of the Iraqi city to achieve a vital cultural communication with the vernacular built heritage, by dealing with the Form-Moral Values structure. Due to its importance within other traditional Iraqi cities, the research chose Al-Kadhimiya as a case study, so it discusses and compares three projects in the competition of developing the surrounding area of Al-Kadhimiya Shrine, in 2009, considering these projects as a clear indication of the recent local approach in dealing with traditional urban configuration. The research reveals a relationship between the type of the traditional urban configuration’s Form-Moral Values bond, and the type of procedures used for it, which could form a vital type of traditional Arab city urban configuration, that keeps the essential characteristics, and in the meantime, responds to the recent demands of the society.","PeriodicalId":52570,"journal":{"name":"Journal of Engineering Science","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85237819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Effect of Fire Flame (High Temperature) on the Self Compacted Concrete (SCC) One Way Slabs 火焰(高温)对自密实混凝土单向板的影响

Journal of Engineering Science Pub Date : 2023-07-22 DOI: 10.31026/j.eng.2012.10.01

Ammar A. Hammadi, A. Izzat, J. Farhan

{"title":"Effect of Fire Flame (High Temperature) on the Self Compacted Concrete (SCC) One Way Slabs","authors":"Ammar A. Hammadi, A. Izzat, J. Farhan","doi":"10.31026/j.eng.2012.10.01","DOIUrl":"https://doi.org/10.31026/j.eng.2012.10.01","url":null,"abstract":"Experimental work was carried out to investigate the effect of fire flame (high temperature) on specimens of one way slabs using Self Compacted Concrete (SCC). By using furnace manufactured for this purpose, twenty one reinforced concrete slab specimens were exposed to direct fire flame. All of specimens have the same dimensions. The slab specimens were cooled in two types, gradually by left them in the air and suddenly by using water. After that the specimens were tested under two point loads, to study, the effect of different: temperature levels (300ºC, 500ºC and 700ºC), and cooling rate (gradually and sudden cooling conditions) on the concrete compressive strength, modulus of rupture, flexural strength and the behavior of reinforced concrete slab specimens and comparing the results with specimens without burning (reference specimens). The results showed that, the concrete compressive strength, concrete modulus of rupture and the flexural strength decreases while the maximum (central) deflection increases with increasing the fire flame temperature. For suddenly cooled specimens the residual flexural strength is less than that of gradually cooled specimens while the deflection is greater. For slabs with 20 MPa concrete strength and gradually cooled, the residual bending strength percent is 81.5%, 75% and 62.3% ,while the increase in central deflection is 5%, 33%, and 105% at burning temperature 300ºC, 500ºC and 700ºC respectively. For suddenly cooled specimens of the same strength and exposed to the same temperatures above the residual flexural strength is 77.9%, 68.3% and 58.3% while the increase in central deflection is 25%, 52%, and 118% respectively. When the strength of concrete specimens increase, the residual flexural strength experiences small increase and the increase is of lower rate in the central deflection for 300 ºC and 500 ºC burn temperatures while the decrease is significant for 700 ºC burning temperature.","PeriodicalId":52570,"journal":{"name":"Journal of Engineering Science","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84668702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Hybrid Controller for a Single Flexible Link Manipulator 单柔性连杆机械臂的混合控制器

Journal of Engineering Science Pub Date : 2023-07-22 DOI: 10.31026/j.eng.2012.11.04

W. K. Sa'id, Bahaa I. Kazem, Alya'a M. Manaty

引用次数: 0

SIMULATION OF OPTIMAL SPEED CONTROL FOR A DC MOTOR USING LINEAR QUADRATIC REGULATOR (LQR) 线性二次型调节器(lqr)直流电机最优调速仿真

Journal of Engineering Science Pub Date : 2023-07-21 DOI: 10.31026/j.eng.2012.03.07

Al-Mulla Hummadi

引用次数: 18

The Effect Of Curing Types On Compressive Strength Of High Performance Concrete 养护类型对高性能混凝土抗压强度的影响

Journal of Engineering Science Pub Date : 2023-07-21 DOI: 10.31026/j.eng.2012.07.01

N. Fawzi, Ahmed Saher, Tawfeeq Agha

引用次数: 3

Cooling and Heating a Greenhouse in Baghdad by a Solar Assisted Desiccant System 利用太阳能辅助干燥剂系统冷却和加热巴格达的温室

Journal of Engineering Science Pub Date : 2023-07-21 DOI: 10.31026/j.eng.2013.08.01

K. A. Joudi, Mustafa Moayad Hasan

{"title":"Cooling and Heating a Greenhouse in Baghdad by a Solar Assisted Desiccant System","authors":"K. A. Joudi, Mustafa Moayad Hasan","doi":"10.31026/j.eng.2013.08.01","DOIUrl":"https://doi.org/10.31026/j.eng.2013.08.01","url":null,"abstract":"Modeling the microclimate of a greenhouse located in Baghdad under its weather conditions to calculate the heating and cooling loads by computer simulation. Solar collectors with a V-corrugated absorber plate and an auxiliary heat source were used as a heating system. A rotary silica gel desiccant dehumidifier, a sensible heat exchanger, and an evaporative cooler were added to the collectors to form an open-cycle solar assisted desiccant cooling system. A dynamic model was adopted to predict the inside air and the soil surface temperatures of the greenhouse. These temperatures are used to predict the greenhouse heating and cooling loads through an energy balance method which takes into account the soil heat gain. This is not included in conventional methods. The results showed satisfactory agreement with published papers. Also, the results of heating and cooling loads obtained revealed good agreement with those obtained from conventional methods when the soil heat gain is included. Two identical collectors in series of total area of 5.4m2 were employed as a heating system which provides an outlet air temperature of 30 o C at air mass flux of 0.06 kg/s.m2 at midday in January. While, a 65 oC outlet air temperature was achieved for the same mass flux at midday in August. The desiccant cooling system was operated in five operating modes; the ventilation mode and four recirculation modes with 20%, 50%, 70%,and 90% recirculation. The simulation results showed that a regeneration temperature of 60-70 o C is satisfactory for a cool supply air temperature of about 19.5 o C. Also, it was noted that 20-30 % recirculation of return air would result in suitable indoor greenhouse conditions for most periods of system operation. In addition, the coefficient of performance COP of the system was high compared with the conventional vapor compression systems.","PeriodicalId":52570,"journal":{"name":"Journal of Engineering Science","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81587657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

FACE IDENTIFICATION USING BACK-PROPAGATION ADAPTIVE MULTIWAVENET 基于反向传播自适应多波网络的人脸识别

Journal of Engineering Science Pub Date : 2023-07-21 DOI: 10.31026/j.eng.2012.03.12

W. A. Mahmoud, A. Abbas, N. Abdul, Sahib Alwan

引用次数: 0