NED University Journal of Research最新文献_第5页

EFFECTS OF WEB OPENINGS ON SHEAR BEHAVIOUR OF NORMAL AND INTERNALLY STRENGTHENED CONCRETE BEAMS 腹板开口对普通和内加筋混凝土梁剪切性能的影响

NED University Journal of Research Pub Date : 1900-01-01 DOI: 10.35453/nedjr-stmech-2019-0020

B. Ahmad, M. Yousaf, Muhammad Irfan-ul-Hassan, M. B. Sharif, Zahid Ahmed Siddiqi, A. Ansari

{"title":"EFFECTS OF WEB OPENINGS ON SHEAR BEHAVIOUR OF NORMAL AND INTERNALLY STRENGTHENED CONCRETE BEAMS","authors":"B. Ahmad, M. Yousaf, Muhammad Irfan-ul-Hassan, M. B. Sharif, Zahid Ahmed Siddiqi, A. Ansari","doi":"10.35453/nedjr-stmech-2019-0020","DOIUrl":"https://doi.org/10.35453/nedjr-stmech-2019-0020","url":null,"abstract":"Web openings in reinforced concrete (RC) beams are provided to pass utility pipes and ducts through them. This causes high stresses (with local cracking) around the transverse web openings, which may lead to reduction in ultimate strength and stiffness of RC beams. Internal strengthening with shear reinforcement can increase ultimate strength of the beam with web openings. This paper presents an experimental study which was conducted to investigate load carrying capacity, mid-span deflection and failure modes of beams with web openings. A total of eighteen RC beams were included in the testing programme, which were tested under two-point loading. The beams contained both pre-planned and post-planned web openings. Experimental results showed that ultimate load of the beams decreased from forty-two to sixty-seven percent due to the presence of web openings in the shear zones. Shear strength of the beams with pre-planned web openings increased by thirty-six percent and one-hundred two percent as compared to the reference beam due to the increase of shear reinforcement by one-hundred twenty-two percent and three-hundred three percent, respectively. Similarly, increase in shear capacity up to six percent and fourteen percent was found for the beams with post-planned web openings due to the aforementioned increase in the area of shear reinforcement, respectively. The ultimate load carrying capacity was also compared with the theoretical models. Internal strengthening and pre planned opening were found effective for providing web openings in the beams.","PeriodicalId":259216,"journal":{"name":"NED University Journal of Research","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126932119","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

CARRIED BAGGAGE DETECTION AND CLASSIFICATION USING MULTI-TREND BINARY CODE DESCRIPTOR AND SUPPORT VECTOR MACHINE 利用多趋势二进制码描述符和支持向量机对随身行李进行检测和分类

NED University Journal of Research Pub Date : 1900-01-01 DOI: 10.35453/nedjr-ascn-2019-0100

Shahana Bano, S. A. Shah, W. Ahmad, Muhammad Ilyas

引用次数: 0

SEISMIC PERFORMANCE ASSESSMENT OF CONFINED ADOBE MASONRY STRUCTURES 约束土坯砌体结构抗震性能评价

NED University Journal of Research Pub Date : 1900-01-01 DOI: 10.35453/nedjr-stmech-2020-0004

Muhammad Ejaz Ahmad, F. Khan, N. Ahmad

{"title":"SEISMIC PERFORMANCE ASSESSMENT OF CONFINED ADOBE MASONRY STRUCTURES","authors":"Muhammad Ejaz Ahmad, F. Khan, N. Ahmad","doi":"10.35453/nedjr-stmech-2020-0004","DOIUrl":"https://doi.org/10.35453/nedjr-stmech-2020-0004","url":null,"abstract":"This paper presents shake-table tests which were performed on two 1:3 reduce-scaled adobe masonry models confined with vertical and horizontal bands. The model AM1 consisted of bands (tie beam) at sill, lintel and eave levels, and lightly reinforced concrete (RC) columns at the corners. The model AM2 was similar to AM1 except that RC columns at the corners were not provided in this model. The models were subjected to sinusoidal base motions for studying their seismic performance. The lateral force-deformation capacity curves for both the models were developed and were bi-linearized to compute the response parameters including stiffness, strength, ductility and response modification factor (R). Seismic performance levels of both the models were defined and their seismic performance assessment was carried out to evaluate their suitability in different seismic zones. The use of vertical columns in the AM1 model considerably increased its lateral strength as compared to the AM2 model. Although R factor of 2.0 has been recommended for both the models, seismic performance of the AM1 model was found better in all seismic zones due to high lateral strength of this model.","PeriodicalId":259216,"journal":{"name":"NED University Journal of Research","volume":"172 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132900541","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

DUCTILITY FACTOR OF REINFORCED CONCRETE FRAME WITH WEAK BEAM-COLUMN JOINT 弱梁柱节点钢筋混凝土框架延性系数

NED University Journal of Research Pub Date : 1900-01-01 DOI: 10.35453/nedjr-stmech-2020-0005

I. Ullah, Muhammad Ejaz Ahmad, N. Ahmad, S. Pervez, Syed Qaisar Abbas

{"title":"DUCTILITY FACTOR OF REINFORCED CONCRETE FRAME WITH WEAK BEAM-COLUMN JOINT","authors":"I. Ullah, Muhammad Ejaz Ahmad, N. Ahmad, S. Pervez, Syed Qaisar Abbas","doi":"10.35453/nedjr-stmech-2020-0005","DOIUrl":"https://doi.org/10.35453/nedjr-stmech-2020-0005","url":null,"abstract":"Code requirements are usually fulfilled during the design of a building. On the other hand, reinforced concrete (RC) frames (particularly in the developing regions of the world) are found deficient due to unregulated constructions. Majority of such deficient structures lack shear reinforcement in beam-column joints. Collapse of these deficient buildings (as a result of limited ductility) triggered many socio-economic and human losses which is evident from recent earthquake disasters. This paper presents an experimental study which was conducted on a 1:4 reduced scale three-storey RC special moment resisting frame (SMRF) lacking shear reinforcement in the beam-column joints. The lack of confinement bars causes shear hinging of joints that reduces the displacement ductility of the frame. Shake-table tests were conducted on test model that was subjected to acceleration time history of 1994 Northridge earthquake, having a peak ground acceleration of 0.57g. The acceleration was linearly scaled to multiple levels and to sinusoidal base excitations of various frequencies and displacements. Moderate to severe damage at each storey level was observed in the joint panels due to the lack of lateral reinforcing ties in the joints. The data obtained from shake table tests were processed and analysed to develop a lateral force-deformation capacity curve, which was bi-linearized as an elasto-plastic curve to compute various response parameters of frame. The ductility factor (RÎ¼) of the tested model was found to be equal to 1.95, which is thirty-five percent less than the code recommended value of RÎ¼ for RC SMRF structures.","PeriodicalId":259216,"journal":{"name":"NED University Journal of Research","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115885303","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

STRUCTURAL ANALYSIS TO IMPROVE THE PERFORMANCE OF A RETRACTABLE JOINTED-CRANE: FAILURE DUE TO OVERLOADING 提高可伸缩铰接起重机性能的结构分析:超载失效

NED University Journal of Research Pub Date : 1900-01-01 DOI: 10.35453/nedjr-stmech-2021-0009

V. Ramírez-Elías, A. Balvantín-García, A. Saldaña-Robles, K. Choo, J. A. Diosdado-De la Peña

{"title":"STRUCTURAL ANALYSIS TO IMPROVE THE PERFORMANCE OF A RETRACTABLE JOINTED-CRANE: FAILURE DUE TO OVERLOADING","authors":"V. Ramírez-Elías, A. Balvantín-García, A. Saldaña-Robles, K. Choo, J. A. Diosdado-De la Peña","doi":"10.35453/nedjr-stmech-2021-0009","DOIUrl":"https://doi.org/10.35453/nedjr-stmech-2021-0009","url":null,"abstract":"This paper proposes a numerical assessment of the after-test failure of a retractable jointed-crane by using finite element analysis (FEA). The original design of the equipment involves a jointed section of coplanar arms and a telescopic section of collinear arms, which complies with the prevalent design standard, applicable for this kind of machinery in Mexico. A prototype of this design was built and was damaged during a beta test, presumably due to a crane misuse. The suggested numerical analysis was carried out in a FEA commercial software by assembling the component by kinematic pairs method, and considering dynamic loads and their resulting reactions at each element. The numerically obtained failure in the components was compared with the observed damage which indicated a difference less than ten percent in the permanent deformation results. Some modifications are recommended on the damaged components to increase the minimum safety factor, reaching up to sixty percent increment in this performance parameter. The causes of the failure are discussed based on the numerical results, and operation recommendations are argued in order to avoid future complications.","PeriodicalId":259216,"journal":{"name":"NED University Journal of Research","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122071339","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

SIMPLE METHOD FOR DETERMINING BENDING STIFFNESS OF LARGE DIAMETER MULTI-LAYERED SPIRAL STRANDS 测定大直径多层螺旋股弯曲刚度的简单方法

NED University Journal of Research Pub Date : 1900-01-01 DOI: 10.35453/nedjr-stmech-2019-0016

S. W. Khan, K. Shahzada, Meraj Alam, M. Fahim, Qazi Sami Ullah, Saeed Zaman, W. Khan

引用次数: 0

EFFECT OF HUMAN HAIR FIBRES ON STRENGTH CHARACTERISTICS OF CONCRETE 人发纤维对混凝土强度特性的影响

NED University Journal of Research Pub Date : 1900-01-01 DOI: 10.35453/nedjr-stmech-2020-0002

S. Ahmed, Aqsa Jamil, Muhammad Irfan-ul-Hassan, Zahid Ahmed Siddiqi

引用次数: 1

APPROPRIATE BOUNDARY CONDITION FOR FINITE ELEMENT ANALYSIS OF STRUCTURAL MEMBER ISOLATED FROM GLOBAL MODEL 脱离整体模型的结构构件有限元分析的适当边界条件

NED University Journal of Research Pub Date : 1900-01-01 DOI: 10.35453/nedjr-stmech-2021-0001

A. Bhutta

{"title":"APPROPRIATE BOUNDARY CONDITION FOR FINITE ELEMENT ANALYSIS OF STRUCTURAL MEMBER ISOLATED FROM GLOBAL MODEL","authors":"A. Bhutta","doi":"10.35453/nedjr-stmech-2021-0001","DOIUrl":"https://doi.org/10.35453/nedjr-stmech-2021-0001","url":null,"abstract":"The wing of a fighter aircraft has various structural members which support aerodynamic and inertial loads, and transmit these loads to the fuselage. As a foremost step to evaluate the structural behaviour of the wing assembly, component contribution analysis is carried out. A finite element analysis of wing tulip of fighter aircraft isolated from the wing was performed under the design load case. Since aircraft wing is a statically indeterminate structure, reaction forces and moments at the supports depend upon the stiffness characteristics of the wing itself. In addition, stiffness of wing also affects the distribution of load and resulting deformation of the wing. These require that support structure of tulip isolated from the global wing model is represented by appropriate boundary conditions for the analysis. A comparative study for three boundary conditions (fixed support, nodal displacements and elastic support) was carried out to determine the representative boundary condition for the analysis of structural members isolated from the global model. It was found that elastic support represents the stiffness of the global model and is a more appropriate boundary condition for the analysis of local models which are isolated from a global model.","PeriodicalId":259216,"journal":{"name":"NED University Journal of Research","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126570529","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