This research work investigated the modeling of Von Mises stress in LNG Spherical Carbon Steel Storage tank using assumed displacement Finite Element analysis based on shallow shell triangular elements. Using equation...This research work investigated the modeling of Von Mises stress in LNG Spherical Carbon Steel Storage tank using assumed displacement Finite Element analysis based on shallow shell triangular elements. Using equations of elasticity, constant thickness carbon steel spherical storage tanks were subjected to different loading conditions. This paper stresses the need for proper definition of shallow element using sector angles to obtain the shallowness. The shallow spherical triangular element has five degrees of freedom at each of its corner node, which are the essential external degrees of freedom. The assumed displacement fields of these shallow triangular elements satisfied the exact requirement of rigid body modes of motion. The FORTRAN 90 programming language was used for the programme coding to solve finite element equations resulting from the model while Von Mises stresses distribution within the spherical storage tank shell subjected to different internal pressures were determined. The results showed that the use of non-shallow elements due to improper sector angles resulted in unreliable results while real shallow elements produced results that tallied with ASME Section VIII Div 1, Part UG values.展开更多
Soil underneath a structure might affect the behavior and the overall response of the structure in seismic events. The role of loose soil conditions and the inclusion of soil-structure interaction (SSI) in the analysi...Soil underneath a structure might affect the behavior and the overall response of the structure in seismic events. The role of loose soil conditions and the inclusion of soil-structure interaction (SSI) in the analysis are important issues that need to be addressed. Since steel structures are light, two configurations designed as spatial and perimeter are considered to study the effect of soil on the steel structural frames for the same building. The paper provides a parametric analysis on the influence of SSI on the overall performance of MRFs (Moment Resisting Frames) according to the provisions of Saudi Building Code (SBC) [1]. A case study has been developed in which spatial and perimeter moment resisting frames of 12, 6 and 3 stories residential buildings are designed using Saudi Building Code (SBC) prescriptions. A modal response spectrum analysis has been carried out to see the influence of SSI on the fundamental period of vibration, top story displacement and inter-story drift limitations. Moreover, a static non-linear analysis has been performed to investigate the performance of frames, thus allowing to identify the influence of SSI on the structural design of steel MRFs.展开更多
This study is focused on?nonlinear analysis and design of?spatial and perimeter moment resisting frames for a 9-storeys?office building?having?9.15?m span.?Seismic?design criteria of Eurocode 8?Ductility Class High (D...This study is focused on?nonlinear analysis and design of?spatial and perimeter moment resisting frames for a 9-storeys?office building?having?9.15?m span.?Seismic?design criteria of Eurocode 8?Ductility Class High (DCH)?with behavior factor (q) of 6.5 and AISC/ASCE code,?Special Moment resisting Frame (SMF) with response modification factor (R) of 8 were employed.?The design outcomes?are?expressed in terms of frame performance?(non-linear analysis), section profiles?(code recommendations), strength-demand to capacity ratios, drift-demand to capacity?ratios and structural weight. The consequences of the research compare?two codes in term of weights and design performances.?This will aid professional engineers and researchers to select effective design criteria and capacity design rules?efficiently.展开更多
The civil engineering profession, in an adaptive reaction to emerging roles for civil engineers, is recognizing the need for new engineers to possess a more robust skill set than just the typical design background. Th...The civil engineering profession, in an adaptive reaction to emerging roles for civil engineers, is recognizing the need for new engineers to possess a more robust skill set than just the typical design background. This paper describes the efforts of Clemson Engineers for Developing Countries （CEDC） to fulfill the more nontraditional and often unaddressed ＂learning outcomes＂ noted by ASCE＇s Civil Engineering Body of Knowledge lbr the 21st Century as important prerequisites for licensure. The learning outcomes are addressed through ongoing international service learning projects in Cange, Haiti. The paper focuses on the following four outcomes and their fulfillment methods： leadership, globalization, teamwork, and communications. The student led organization has allowed students to set up their own fundraising mechanisms, to seek out members to join design review boards, and to develop their own project objectives. This level of student autonomy is n,3ted as key to ensuring that students achieve competency in these four areas.展开更多
Elastic wave-based non-destructive testing(NDT) methods are effective for flaw detection in concrete structures and pavements.However,the test speed of elastic wave-based methods is severely limited by the physical co...Elastic wave-based non-destructive testing(NDT) methods are effective for flaw detection in concrete structures and pavements.However,the test speed of elastic wave-based methods is severely limited by the physical coupling between sensors and concrete surface.The air-coupled sensing method is proposed as a solution to develop rapid NDT techniques for concrete infrastructure.This paper reviews the development of air-coupled sensing technique for concrete structures in civil engineering applications.It presents four stages of the research:1) feasibility study through theoretical analysis;2) air-coupled surface wave velocity measurement; 3) air-coupled surface wave transmission measurement to determine crack depth;4) air-coupled impact -echo test to locate delaminations and voids in concrete.展开更多
文摘This research work investigated the modeling of Von Mises stress in LNG Spherical Carbon Steel Storage tank using assumed displacement Finite Element analysis based on shallow shell triangular elements. Using equations of elasticity, constant thickness carbon steel spherical storage tanks were subjected to different loading conditions. This paper stresses the need for proper definition of shallow element using sector angles to obtain the shallowness. The shallow spherical triangular element has five degrees of freedom at each of its corner node, which are the essential external degrees of freedom. The assumed displacement fields of these shallow triangular elements satisfied the exact requirement of rigid body modes of motion. The FORTRAN 90 programming language was used for the programme coding to solve finite element equations resulting from the model while Von Mises stresses distribution within the spherical storage tank shell subjected to different internal pressures were determined. The results showed that the use of non-shallow elements due to improper sector angles resulted in unreliable results while real shallow elements produced results that tallied with ASME Section VIII Div 1, Part UG values.
文摘Soil underneath a structure might affect the behavior and the overall response of the structure in seismic events. The role of loose soil conditions and the inclusion of soil-structure interaction (SSI) in the analysis are important issues that need to be addressed. Since steel structures are light, two configurations designed as spatial and perimeter are considered to study the effect of soil on the steel structural frames for the same building. The paper provides a parametric analysis on the influence of SSI on the overall performance of MRFs (Moment Resisting Frames) according to the provisions of Saudi Building Code (SBC) [1]. A case study has been developed in which spatial and perimeter moment resisting frames of 12, 6 and 3 stories residential buildings are designed using Saudi Building Code (SBC) prescriptions. A modal response spectrum analysis has been carried out to see the influence of SSI on the fundamental period of vibration, top story displacement and inter-story drift limitations. Moreover, a static non-linear analysis has been performed to investigate the performance of frames, thus allowing to identify the influence of SSI on the structural design of steel MRFs.
文摘This study is focused on?nonlinear analysis and design of?spatial and perimeter moment resisting frames for a 9-storeys?office building?having?9.15?m span.?Seismic?design criteria of Eurocode 8?Ductility Class High (DCH)?with behavior factor (q) of 6.5 and AISC/ASCE code,?Special Moment resisting Frame (SMF) with response modification factor (R) of 8 were employed.?The design outcomes?are?expressed in terms of frame performance?(non-linear analysis), section profiles?(code recommendations), strength-demand to capacity ratios, drift-demand to capacity?ratios and structural weight. The consequences of the research compare?two codes in term of weights and design performances.?This will aid professional engineers and researchers to select effective design criteria and capacity design rules?efficiently.
文摘The civil engineering profession, in an adaptive reaction to emerging roles for civil engineers, is recognizing the need for new engineers to possess a more robust skill set than just the typical design background. This paper describes the efforts of Clemson Engineers for Developing Countries （CEDC） to fulfill the more nontraditional and often unaddressed ＂learning outcomes＂ noted by ASCE＇s Civil Engineering Body of Knowledge lbr the 21st Century as important prerequisites for licensure. The learning outcomes are addressed through ongoing international service learning projects in Cange, Haiti. The paper focuses on the following four outcomes and their fulfillment methods： leadership, globalization, teamwork, and communications. The student led organization has allowed students to set up their own fundraising mechanisms, to seek out members to join design review boards, and to develop their own project objectives. This level of student autonomy is n,3ted as key to ensuring that students achieve competency in these four areas.
基金sponsored by the National Science Foundation under Grant No.CMS-0223819started up funds provided by the University of Texas at Austin
文摘Elastic wave-based non-destructive testing(NDT) methods are effective for flaw detection in concrete structures and pavements.However,the test speed of elastic wave-based methods is severely limited by the physical coupling between sensors and concrete surface.The air-coupled sensing method is proposed as a solution to develop rapid NDT techniques for concrete infrastructure.This paper reviews the development of air-coupled sensing technique for concrete structures in civil engineering applications.It presents four stages of the research:1) feasibility study through theoretical analysis;2) air-coupled surface wave velocity measurement; 3) air-coupled surface wave transmission measurement to determine crack depth;4) air-coupled impact -echo test to locate delaminations and voids in concrete.
