Pub Date : 2021-06-30DOI: 10.33261/jaaru.2021.28.2.008
T. M. S. AL-ansari, Asmaa.M.H. Al-Moqaram
The relationship between the structure and the shape in contemporary architecture has different formatsaccording to design and structural requirements. The integration is important formulas among these relationship, asthey form one unit in architecture, where the integration is characteristic by the important property which is theiterative system. One of the strategies to find iterative systems in contemporary architecture over traditional is calledstructural surface. Previous knowledge has been differed in explaining the functional of systems and it’smechanisms, especially in the relationship among the form and structure, so the problem has surfaced “the necessityto know the difference of the properties and types of iterative systems among solid and perforated structures withinthe structural surface strategy, and it’s role between the form and the structure”. to achieve the research’s goal “whatare the repetition and iterative systems in contemporary architectural structure and it’s role to determine the shape ofthe relationship among the structure and the form for building of different heights “, which has depended ondescriptive analytical method in three stage after defining the repetition in general, iterative system in particular andprevious knowledge criticism. First stage has focused on building a theoretical framework (characteristics and typesof the iterative systems in contemporary architectural structure and structural surface strategy). Second stage hasfocused on knowing the levels of the relationship among the form and the structure, By studying selected sampleswithin building of different height In addition to determine the important basic assumption of the research ,which is(iterative systems is differ in architectural structure (solid and perforated) , through characteristics of the iterativesystems with the system and the relationship of the surrounding environment according to it’s height (high ,medium)and it’s formation method (orthogonal ,free) ) . Third stage has focused on analyzing the results and conclusions as inthe role of the iterative systems (structural surface strategy) in producing the solid structures by adopting therepetition of the structural elements and generative rules in perforated structures, and use it to achieve a fusionamong the form and the structure to produce structures with efficiency and aesthetic appearance and structures thatreflect movement and dynamism. The level of this relationship are :( first: the compositionl, through theorganizational depth of the architectural structure. Second: the expressive, by finding three types of the relationshipare (the merging, the discrete, and the hybrid).
{"title":"Iterative systems in sold structures and filigree structures / study in structural surface strategy","authors":"T. M. S. AL-ansari, Asmaa.M.H. Al-Moqaram","doi":"10.33261/jaaru.2021.28.2.008","DOIUrl":"https://doi.org/10.33261/jaaru.2021.28.2.008","url":null,"abstract":"The relationship between the structure and the shape in contemporary architecture has different formatsaccording to design and structural requirements. The integration is important formulas among these relationship, asthey form one unit in architecture, where the integration is characteristic by the important property which is theiterative system. One of the strategies to find iterative systems in contemporary architecture over traditional is calledstructural surface. Previous knowledge has been differed in explaining the functional of systems and it’smechanisms, especially in the relationship among the form and structure, so the problem has surfaced “the necessityto know the difference of the properties and types of iterative systems among solid and perforated structures withinthe structural surface strategy, and it’s role between the form and the structure”. to achieve the research’s goal “whatare the repetition and iterative systems in contemporary architectural structure and it’s role to determine the shape ofthe relationship among the structure and the form for building of different heights “, which has depended ondescriptive analytical method in three stage after defining the repetition in general, iterative system in particular andprevious knowledge criticism. First stage has focused on building a theoretical framework (characteristics and typesof the iterative systems in contemporary architectural structure and structural surface strategy). Second stage hasfocused on knowing the levels of the relationship among the form and the structure, By studying selected sampleswithin building of different height In addition to determine the important basic assumption of the research ,which is(iterative systems is differ in architectural structure (solid and perforated) , through characteristics of the iterativesystems with the system and the relationship of the surrounding environment according to it’s height (high ,medium)and it’s formation method (orthogonal ,free) ) . Third stage has focused on analyzing the results and conclusions as inthe role of the iterative systems (structural surface strategy) in producing the solid structures by adopting therepetition of the structural elements and generative rules in perforated structures, and use it to achieve a fusionamong the form and the structure to produce structures with efficiency and aesthetic appearance and structures thatreflect movement and dynamism. The level of this relationship are :( first: the compositionl, through theorganizational depth of the architectural structure. Second: the expressive, by finding three types of the relationshipare (the merging, the discrete, and the hybrid).","PeriodicalId":414074,"journal":{"name":"Association of Arab Universities Journal of Engineering Sciences","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116598555","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}
Pub Date : 2021-06-30DOI: 10.33261/jaaru.2021.28.2.005
Dareen Al Salamah, Ghandi Jahjah, Ihsan Al Tarsh
— The strength of reinforced concrete beams is reduced to high extent when openings are created in their webs, so it is necessary to strengthen these beams by any modern strengthening methods to restore the strength of the beams before openings are created in their webs to continue in use of these beams. Analytical study is presented in this research to study CFRP strengthening effect around created opening in reinforced concrete beams under torsion and bending. The research depends on finite element method using Ansys 15. It is used SOLID65 to model concrete beam, SOLID 185 to model CFRP, supports and steel arms, and LINK 181 for long steel and stripes. Then analytical model is built to model reinforced concrete beams. This model gives results which are closed to experimental results.
{"title":"Experimental-Analytical Study of CFRP strengthening Effect of Reinforced Concrete Beams with Web Opening under Torsion and Bending","authors":"Dareen Al Salamah, Ghandi Jahjah, Ihsan Al Tarsh","doi":"10.33261/jaaru.2021.28.2.005","DOIUrl":"https://doi.org/10.33261/jaaru.2021.28.2.005","url":null,"abstract":"— The strength of reinforced concrete beams is reduced to high extent when openings are created in their webs, so it is necessary to strengthen these beams by any modern strengthening methods to restore the strength of the beams before openings are created in their webs to continue in use of these beams. Analytical study is presented in this research to study CFRP strengthening effect around created opening in reinforced concrete beams under torsion and bending. The research depends on finite element method using Ansys 15. It is used SOLID65 to model concrete beam, SOLID 185 to model CFRP, supports and steel arms, and LINK 181 for long steel and stripes. Then analytical model is built to model reinforced concrete beams. This model gives results which are closed to experimental results.","PeriodicalId":414074,"journal":{"name":"Association of Arab Universities Journal of Engineering Sciences","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132765260","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}
Pub Date : 2021-06-30DOI: 10.33261/jaaru.2021.28.2.009
Mohamad Radawn Bazat, Mohamad Yahay Zien AL-deen, Hasan AL-Khamisy
Preparation of o-carboxymethyl Chitosan was done, wich is important derivative of chitosan. Grafting copolymerization of acrylonitrile onto o-carboxymethyl chitosan was accomplished using ammonium cerium sulfate (CAS) as an initiator. Resulting graft of o-carboxymethyl chitosan was characterized by FT-IR spectrum and DTA analysis to be compared with o-carboxymethyl chitosan. Properties such as water swelling and solubility were studied for each, whereas,. Percentage of grafting efficiency (GE%) and yield of grafting (GY%) were determined. The efficiency of grafted ocarboxymethyl chitosan (CMCh-g-PAN) to remove dyes(direct black dyes, dispersed red dyes) from industrial waste water was also determined. The results reveal good efficient absorption of black dyes more than red dyes. Efficiency from different concentrations of grafted o-carboxymethyl chitosan(CMCh-g-PAN) to reveal percentages of elimination ions from their solutions metallic ions Cu2+,Pb2+,Cd2+and Sn2+ from their solutions at room temperature with mechanical stirring for 24 hrs were also determined .It has been shown that grafted o-carboxymethyl chitosan has important role in elimination of lead ion comparing with other ions, As a result, elimination percentages of ions increase as follow: Cd2+< Sn2+< Cu2+<. Pb2+
{"title":"Grafting of O-Carboxymethyl Chitosan with Acrylonitrile and Studying some of its Properties and Applications","authors":"Mohamad Radawn Bazat, Mohamad Yahay Zien AL-deen, Hasan AL-Khamisy","doi":"10.33261/jaaru.2021.28.2.009","DOIUrl":"https://doi.org/10.33261/jaaru.2021.28.2.009","url":null,"abstract":"Preparation of o-carboxymethyl Chitosan was done, wich is important derivative of chitosan. Grafting copolymerization of acrylonitrile onto o-carboxymethyl chitosan was accomplished using ammonium cerium sulfate (CAS) as an initiator. Resulting graft of o-carboxymethyl chitosan was characterized by FT-IR spectrum and DTA analysis to be compared with o-carboxymethyl chitosan. Properties such as water swelling and solubility were studied for each, whereas,. Percentage of grafting efficiency (GE%) and yield of grafting (GY%) were determined. The efficiency of grafted ocarboxymethyl chitosan (CMCh-g-PAN) to remove dyes(direct black dyes, dispersed red dyes) from industrial waste water was also determined. The results reveal good efficient absorption of black dyes more than red dyes. Efficiency from different concentrations of grafted o-carboxymethyl chitosan(CMCh-g-PAN) to reveal percentages of elimination ions from their solutions metallic ions Cu2+,Pb2+,Cd2+and Sn2+ from their solutions at room temperature with mechanical stirring for 24 hrs were also determined .It has been shown that grafted o-carboxymethyl chitosan has important role in elimination of lead ion comparing with other ions, As a result, elimination percentages of ions increase as follow: Cd2+< Sn2+< Cu2+<. Pb2+","PeriodicalId":414074,"journal":{"name":"Association of Arab Universities Journal of Engineering Sciences","volume":"7 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132339947","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}
Pub Date : 2021-06-30DOI: 10.33261/jaaru.2021.28.2.010
Ali Alhaidar, Ali Ali, M. Shash
In this study, the effect of adding barium sulfate as a filler in the properties of NBR has been studied bypreparing blends of rubber containing different proportions of barium sulfate ( 20 0 phr) , ,1,3,5,10,15, on two roll millthen describe Physio - mechanical and chemical properties of the prepared blends were described by testing them fortensile strength and abrasion resistance, value of hardness and swelling in different solvents. The results showed anincrease in tensile strength by (6.1%) with an increase in the percentage of barium sulfate within the rubber mixturesuntil (1phr), then the tensile strength decreased with an increase in the ratio of barium sulfate in the rubbercompositions over (1phr). As for elongation at break, it gradually increased by (74.4%) at the rate of adding (1 phr)and then decreased with increasing the percentage of barium sulfate to (phr5) and then increased with the increase ofbarium sulfate. While the hardness values decreased by (14.9%) with the increase in the percentage of barium sulfateto the ratio of (phr20), friction resistance also decreased by (45.83%) with an increase in the percentage of bariumsulfate to (phr20). The results of the study also showed that the productivity of samples containing black carbon only(C45B0) was very low compared to samples containing barium sulfate.
{"title":"The effect of barium sulfate as a filler on the physical and mechanical properties of nitrile rubber blends","authors":"Ali Alhaidar, Ali Ali, M. Shash","doi":"10.33261/jaaru.2021.28.2.010","DOIUrl":"https://doi.org/10.33261/jaaru.2021.28.2.010","url":null,"abstract":"In this study, the effect of adding barium sulfate as a filler in the properties of NBR has been studied bypreparing blends of rubber containing different proportions of barium sulfate ( 20 0 phr) , ,1,3,5,10,15, on two roll millthen describe Physio - mechanical and chemical properties of the prepared blends were described by testing them fortensile strength and abrasion resistance, value of hardness and swelling in different solvents. The results showed anincrease in tensile strength by (6.1%) with an increase in the percentage of barium sulfate within the rubber mixturesuntil (1phr), then the tensile strength decreased with an increase in the ratio of barium sulfate in the rubbercompositions over (1phr). As for elongation at break, it gradually increased by (74.4%) at the rate of adding (1 phr)and then decreased with increasing the percentage of barium sulfate to (phr5) and then increased with the increase ofbarium sulfate. While the hardness values decreased by (14.9%) with the increase in the percentage of barium sulfateto the ratio of (phr20), friction resistance also decreased by (45.83%) with an increase in the percentage of bariumsulfate to (phr20). The results of the study also showed that the productivity of samples containing black carbon only(C45B0) was very low compared to samples containing barium sulfate.","PeriodicalId":414074,"journal":{"name":"Association of Arab Universities Journal of Engineering Sciences","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123680524","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}
Pub Date : 2021-06-30DOI: 10.33261/jaaru.2021.28.2.007
Mohamad Yehea Al nefawy, Fouad El Dahiye
Retrogression and Re-Aging (RRA) Heat Treatment improves the tensile of aluminum alloys. In this research, to study the effect of Retrogression temperature and Retrogression time on the hardness, tensile strength and microstructure of 7075 aluminum alloy, have been applied. Retrogression treatments at different temperatures 180°C, 240°C and 370°C for 30 min and 90 min. When the retrogression temperature was 180°C for 30 min, the alloy has reached its highest hardness and tensile strength; they were respectively 165 HB and 586 MPa. RRA treatment of aluminum alloy 7075 led to precipitate a smoother, more homogeneous, and denser phase compared to the T6 treatment.
{"title":"Effect of Retrogression and Re-Aging Heat Treatment on Hardness, Tensile Strength and Microstructure of 7075 Aluminum Alloy","authors":"Mohamad Yehea Al nefawy, Fouad El Dahiye","doi":"10.33261/jaaru.2021.28.2.007","DOIUrl":"https://doi.org/10.33261/jaaru.2021.28.2.007","url":null,"abstract":"Retrogression and Re-Aging (RRA) Heat Treatment improves the tensile of aluminum alloys. In this research, to study the effect of Retrogression temperature and Retrogression time on the hardness, tensile strength and microstructure of 7075 aluminum alloy, have been applied. Retrogression treatments at different temperatures 180°C, 240°C and 370°C for 30 min and 90 min. When the retrogression temperature was 180°C for 30 min, the alloy has reached its highest hardness and tensile strength; they were respectively 165 HB and 586 MPa. RRA treatment of aluminum alloy 7075 led to precipitate a smoother, more homogeneous, and denser phase compared to the T6 treatment.","PeriodicalId":414074,"journal":{"name":"Association of Arab Universities Journal of Engineering Sciences","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131319126","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}
Pub Date : 2021-06-30DOI: 10.33261/jaaru.2021.28.2.003
Jinan Hasan Madhlom
All Marketing has a major role in professional practice, especially in architectural professing. The marketing provides a great benefit to the architect, especially if he develops this profession. Day by day, The architectural profession is becoming more competitive, as it needs to learn more about advanced marketing techniques. many architects are follow the old ways of gaining customers' reputation, and these methods do not correspond to the era of modernity in the architectural business environment and preparing competitors .So the problem surfaced(Lack of adoption of marketing as an important factor in the success of architectural offices, therefore it is necessary to search for the concept of marketing and what its plans and it’s strategies ) ,The research goal is "searching for the concept of marketing and determining what it’s plans and it’s strategies", Research hypothesis: "a successful marketing plan means getting more customers and thus more profits”. So must be three-stage approach, first: building a theoretical framework on marketing plans and strategies. Second: applying the vocabulary of the theoretical framework to an elected sample of architectural offices. Third: analyzing the results and extracting the conclusions, to conclude that there is a lack of awareness on the importance of marketing in the architectural business environment in Iraq, and the adoption of marketing as a method between offices and architectural companies to increase customers and thus increase profits.
{"title":"The role of marketing in promoting the profession of architecture: The environment of Iraqi architectural offices is a case study","authors":"Jinan Hasan Madhlom","doi":"10.33261/jaaru.2021.28.2.003","DOIUrl":"https://doi.org/10.33261/jaaru.2021.28.2.003","url":null,"abstract":"All Marketing has a major role in professional practice, especially in architectural professing. The marketing provides a great benefit to the architect, especially if he develops this profession. Day by day, The architectural profession is becoming more competitive, as it needs to learn more about advanced marketing techniques. many architects are follow the old ways of gaining customers' reputation, and these methods do not correspond to the era of modernity in the architectural business environment and preparing competitors .So the problem surfaced(Lack of adoption of marketing as an important factor in the success of architectural offices, therefore it is necessary to search for the concept of marketing and what its plans and it’s strategies ) ,The research goal is \"searching for the concept of marketing and determining what it’s plans and it’s strategies\", Research hypothesis: \"a successful marketing plan means getting more customers and thus more profits”. So must be three-stage approach, first: building a theoretical framework on marketing plans and strategies. Second: applying the vocabulary of the theoretical framework to an elected sample of architectural offices. Third: analyzing the results and extracting the conclusions, to conclude that there is a lack of awareness on the importance of marketing in the architectural business environment in Iraq, and the adoption of marketing as a method between offices and architectural companies to increase customers and thus increase profits.","PeriodicalId":414074,"journal":{"name":"Association of Arab Universities Journal of Engineering Sciences","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128283188","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}
Pub Date : 2021-06-30DOI: 10.33261/jaaru.2021.28.2.006
Waad Ibrahim Alkhatib, Ghandy Ali Jahjah
{"title":"Experemntal and Statistical Study on the Most Important Parameters Affected on the Shear Resistance of Self- Compacting Concrete Beams Without Stirrups","authors":"Waad Ibrahim Alkhatib, Ghandy Ali Jahjah","doi":"10.33261/jaaru.2021.28.2.006","DOIUrl":"https://doi.org/10.33261/jaaru.2021.28.2.006","url":null,"abstract":"","PeriodicalId":414074,"journal":{"name":"Association of Arab Universities Journal of Engineering Sciences","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128889780","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}
Pub Date : 2021-06-30DOI: 10.33261/jaaru.2021.28.2.004
Mais Ghassoun, Ali Algharrash, Reem Alsehnawi
The Dynamic characteristics such as damping ratio and natural frequency are an important indicator for predicting the dynamic behavior of bridges, but it is customary during the design that the designer assess the dynamic properties of the dynamic analysis because it is very difficult to determine the damping of the origin before construction and damping is taken as a predetermined constant value independent of the response amplitude and frequency of the structure. In the dynamic analysis of constructions design some experimental research has been concerned with the determination of dynamic structural properties and their relationship with the response amplitude experimentally, but the changes in dynamic properties with vibration amplitude has never been taken During dynamic analysis, further analytical treatments and computer modeling were required to study different cases based on the experimental results available by simulating them with a computer model. Dynamic characteristics are very essential to accurately determine the dynamic response, and it is necessary to study the effect of changes of the actual dynamic characteristics of bridges, which were determined by measuring their vibration in the results of dynamic analysis and comparing them with results that do not take into account the changes of dynamic properties and with laboratory results in order to assess the role of. Dynamic analysis inputs in simulating vibrations by monitoring their responses. As a result, it was found that the dynamic properties are independent of the shape of the external exactions. Also, it was concluded that relationships express the change of dynamic properties in terms of vibration amplitudes. And Similar reliance of the dynamic characteristics to the vibration amplitude is confirmed for the pier model, where the increase of the amplitude of the acceleration is accompanied by a decrease in the natural frequency, and an increase in the damping ratio is obvious. Before choosing design values when considering the dynamic characteristics of a structure, we need to give unique concentration to the predictable vibration amplitudes. Dynamic characteristics changes during dynamic analysis should be considered to produce analytical results that simulate experimental results and are closer to reality.
{"title":"Study On The Vibration Amplitudes Of Reinforced Concrete Bridge Piers Using ABAQUS Software","authors":"Mais Ghassoun, Ali Algharrash, Reem Alsehnawi","doi":"10.33261/jaaru.2021.28.2.004","DOIUrl":"https://doi.org/10.33261/jaaru.2021.28.2.004","url":null,"abstract":"The Dynamic characteristics such as damping ratio and natural frequency are an important indicator for predicting the dynamic behavior of bridges, but it is customary during the design that the designer assess the dynamic properties of the dynamic analysis because it is very difficult to determine the damping of the origin before construction and damping is taken as a predetermined constant value independent of the response amplitude and frequency of the structure. In the dynamic analysis of constructions design some experimental research has been concerned with the determination of dynamic structural properties and their relationship with the response amplitude experimentally, but the changes in dynamic properties with vibration amplitude has never been taken During dynamic analysis, further analytical treatments and computer modeling were required to study different cases based on the experimental results available by simulating them with a computer model. Dynamic characteristics are very essential to accurately determine the dynamic response, and it is necessary to study the effect of changes of the actual dynamic characteristics of bridges, which were determined by measuring their vibration in the results of dynamic analysis and comparing them with results that do not take into account the changes of dynamic properties and with laboratory results in order to assess the role of. Dynamic analysis inputs in simulating vibrations by monitoring their responses. As a result, it was found that the dynamic properties are independent of the shape of the external exactions. Also, it was concluded that relationships express the change of dynamic properties in terms of vibration amplitudes. And Similar reliance of the dynamic characteristics to the vibration amplitude is confirmed for the pier model, where the increase of the amplitude of the acceleration is accompanied by a decrease in the natural frequency, and an increase in the damping ratio is obvious. Before choosing design values when considering the dynamic characteristics of a structure, we need to give unique concentration to the predictable vibration amplitudes. Dynamic characteristics changes during dynamic analysis should be considered to produce analytical results that simulate experimental results and are closer to reality.","PeriodicalId":414074,"journal":{"name":"Association of Arab Universities Journal of Engineering Sciences","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128725482","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}
Pub Date : 2021-03-31DOI: 10.33261/JAARU.2021.28.1.010
Ali Alhaidar, Ali Ali, M. Shash
This research studies the effect of adding the clinker as a filling material on the properties of Acrylonitrilebutadiene rubber NBR ،by means of preparing rubber blends containing different percentage (0,5,10,15,20 Phr) of theclinker (Semi made-cement) ،on two roll mill. Physio -mechanical and chemical properties of the prepared blends weredescribed by testing them for tensile strength and abrasion resistance, values of hardness and swelling in differentsolvents. Results revealed a decrease in the tension resistance for rubber blends c/k at the percentage of 45% withincrease of the percentage of the clinker added with the above mentioned rubber blends ,Also ,values of hardnessdecreased direct proportional at a percentage of 19% with increasing the clinker ,percentage whereas, the frictionresistance decreased at a percentage of 254% with increasing the clinker percentage ,but according to elongation ,theresults were quite different from the previous results so that its percentage increased when cutting gradually with thevalue of 266%when percentage of added clinker increased. Results of the study also, revealed that swelling of thesamples containing only the black carbon (C45K0) was low comparing with the samples containing the clinker.
{"title":"Studying the physical and mechanical properties of Acrylonitrile butadiene rubber / carbon / clinke","authors":"Ali Alhaidar, Ali Ali, M. Shash","doi":"10.33261/JAARU.2021.28.1.010","DOIUrl":"https://doi.org/10.33261/JAARU.2021.28.1.010","url":null,"abstract":"This research studies the effect of adding the clinker as a filling material on the properties of Acrylonitrilebutadiene rubber NBR ،by means of preparing rubber blends containing different percentage (0,5,10,15,20 Phr) of theclinker (Semi made-cement) ،on two roll mill. Physio -mechanical and chemical properties of the prepared blends weredescribed by testing them for tensile strength and abrasion resistance, values of hardness and swelling in differentsolvents. Results revealed a decrease in the tension resistance for rubber blends c/k at the percentage of 45% withincrease of the percentage of the clinker added with the above mentioned rubber blends ,Also ,values of hardnessdecreased direct proportional at a percentage of 19% with increasing the clinker ,percentage whereas, the frictionresistance decreased at a percentage of 254% with increasing the clinker percentage ,but according to elongation ,theresults were quite different from the previous results so that its percentage increased when cutting gradually with thevalue of 266%when percentage of added clinker increased. Results of the study also, revealed that swelling of thesamples containing only the black carbon (C45K0) was low comparing with the samples containing the clinker.","PeriodicalId":414074,"journal":{"name":"Association of Arab Universities Journal of Engineering Sciences","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130468484","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}
Pub Date : 2021-03-31DOI: 10.33261/JAARU.2021.28.1.001
Ali F. Kadhim, H. A. Thamiry
The pumping station is widely used in our modern life. The occurrence of the vortex at pumpsump, which is causing air entering pipe intake, is a common problem in the design of pumps. Thisphenomenon, including surface and sub-surface vortex, may lead to damage to the pumping structure, highpower consumption, and loss in pump performance. In some requirements, the multiple suction pipes areusing to get the required flow. Due to this arrangement, the performance of the suction pipes will influence.This paper is aimed to investigate the occurrence of vortices around the flow pattern of two pumps by usingComputational Fluid Dynamic (CFD) code Fluent. This CFD model is based on solving Navier-Stockequations by finite volume method. The model of double suction pipes was investigated under five differentsubmergence depth (S) and five different suction velocities (v). The SST k-ω turbulence model was selectedfor the turbulence. The results showed that the air entering vortex does not appear when the submergencedepth (S) is equal or greater than 1.5 times from the diameter of the bellmouth for intake pipe (D). Thesurface vortex appeared obviously when the submergence depth (S) equals to 1.25D and the Froude numberat the bell is equal to or greater than 1.028, and appeared clearly when the (S/D=1) and Froude number isequal to or more than 0.77. The nearer attached wall vortex does not appear when the space from the centerof the suction pipe to the sidewall (C) equals 2 times of bell diameter.
{"title":"Numerical Simulation to Investigate the Occurrence of Vortices at Double Vertical Pumps Intakes","authors":"Ali F. Kadhim, H. A. Thamiry","doi":"10.33261/JAARU.2021.28.1.001","DOIUrl":"https://doi.org/10.33261/JAARU.2021.28.1.001","url":null,"abstract":"The pumping station is widely used in our modern life. The occurrence of the vortex at pumpsump, which is causing air entering pipe intake, is a common problem in the design of pumps. Thisphenomenon, including surface and sub-surface vortex, may lead to damage to the pumping structure, highpower consumption, and loss in pump performance. In some requirements, the multiple suction pipes areusing to get the required flow. Due to this arrangement, the performance of the suction pipes will influence.This paper is aimed to investigate the occurrence of vortices around the flow pattern of two pumps by usingComputational Fluid Dynamic (CFD) code Fluent. This CFD model is based on solving Navier-Stockequations by finite volume method. The model of double suction pipes was investigated under five differentsubmergence depth (S) and five different suction velocities (v). The SST k-ω turbulence model was selectedfor the turbulence. The results showed that the air entering vortex does not appear when the submergencedepth (S) is equal or greater than 1.5 times from the diameter of the bellmouth for intake pipe (D). Thesurface vortex appeared obviously when the submergence depth (S) equals to 1.25D and the Froude numberat the bell is equal to or greater than 1.028, and appeared clearly when the (S/D=1) and Froude number isequal to or more than 0.77. The nearer attached wall vortex does not appear when the space from the centerof the suction pipe to the sidewall (C) equals 2 times of bell diameter.","PeriodicalId":414074,"journal":{"name":"Association of Arab Universities Journal of Engineering Sciences","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116910384","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：