Wind turbines are designed and analyzed using simulation tools capable of predicting the coupled dynamic loads and responses of the system. In this paper, an overview of the capabilities of a Computer-Aided Engineering (CAE) tool called FAST or Fatigue, Aerodynamic, Structures, and Turbulence in modeling wind turbines in different depths of water will be presented. Different offshore wind turbine support systems structures will be discussed. These support systems are classified into three categories according to the water depth, namely, shallow water, translational water and deep water depths. This paper will be focusing on the support structures used in translational and deep water depths only. This will also be focusing on incorporating hydrodynamic loading for multimember structures using FAST through its hydrodynamic loading module, Hydrodyn. Also, a quantitative comparison of th*e responses of different floating platforms will be tackled.

This study aims to give a brief summary of the development in the series of studies that have been made regarding the lateral-torsional buckling (LTB) capacity of beam spans with increased cross section at one end, also known as singly stepped beam (SSB), and at both ends, also known as doubly stepped beam (DSB). A three-dimensional program ABAQUS was used to analyze buckling through finite element method, while a statistical regression program MINITAB was used in developing and proposing simple design equations. The following topics discussed in this study include: (1) proposed design equation that account for change in cross section of stepped beams under uniform moment; (2) proposed design equation, with a corresponding moment gradient factor equation, of stepped beams under general loading conditions; (3) proposed design equation for stepped beam with continuous top flange lateral bracing; (4) proposed design equation for monosymmetric stepped beam subjected to uniform moment and to general loading conditions; (5) effect of inelastic buckling of stepped beams subjected to pure bending and general loading conditions considering combined effects of residual stress and geometrical imperfection; and (6) determination of LTB strength of monosymmetric stepped beam by conducting destructive test of subjecting a beam to concentrated load. The summary presented provides researchers information in understanding the subject matter; moreover, this provides a meaningful contribution to futures researches.

This study is all about the presentation of the results of the analyses made to determine the inelastic lateral torsional buckling strength of singly symmetric singly stepped I-beam with constant depth subjected to basic loading condition. A finite element program ABAQUS and a regression program MINITAB are used to analyze the simply supported singly symmetric singly stepped I-beams having singly symmetric ratio, ρ, of 0.1 to 0.9 and a Lb/h ratio of 4.5. Using the results of the analyses made, a design equation is suggested that can easily calculate the stepped beam correction factor Cist which then can be used to determine the inelastic lateral torsional buckling strength of singly symmetric singly stepped I-beams subjected to pure bending moment. Then, the results from the equation proposed are compared with the results obtained from the finite element analysis. The results obtained show acceptable results for singly stepped beams having a ρ of 0.3 to 0.9 and a very conservative result for a ρ of 0.1.

Recently, as the level of market competition in the structural engineering field continues to rise, structural designers are finding other ways to make their designs stand out. One way of doing that is to make the designs more economical without sacrificing efficiency. As a result, the use of stepped beams and the studies involving it has become more common. Stepped beams are beams that have a sudden increase in cross section along its length. The change in cross section is made by increasing the width and/or the thickness of the flanges along a certain length while maintaining the dimensions of the web. Most of the studies involving lateral torsional buckling of stepped beams are focused on developing equations and studying the effects of symmetry. However, the studies involving actual test experiments are still very limited. Thus, this study has three main objectives. The first objective of this study is to give a brief historical overview on the series of studies involving the lateral torsional buckling capacity of stepped beams and give an idea on its current state of the art. The second objective is to determine if the intuitive expectation that the lowest critical moment always corresponds to uniform bending moment holds true for stepped beams. The degree of symmetry is varied and several loading conditions are observed. The third objective of this study is to determine the actual inelastic lateral torsional buckling capacity of doubly stepped singly symmetric I-beams having compact and non-compact flange sections subjected to two point loading condition and to use the results obtained to determine the applicability of previously proposed equations in predicting the buckling strength of stepped beams. The results are obtained by conducting actual destructive tests on doubly stepped I-beams using a universal testing machine and running simulation tests using the finite element program, ABAQUS. The main factors that are considered for the experimental and finite element analysis are the degree of beam symmetry, the loading condition, the supports, the stepped beam factors and the unsupported length. The degree of symmetry of all the stepped beams analyzed is fixed at 0.7. The unsupported lengths of the beams analyzed are 3 meters and 4 meters. The results obtained from the analysis are compared with the results from design specifications to determine the effects of steps and from proposed design equations to determine the equations’ applicability and safety. Finally, the results revealed that the stepped beams did have an increase in lateral torsional buckling capacity in comparison with the prismatic beams and that the proposed equations are suitable to be used in predicting the strength of stepped beams having compact flanges under the observed loading condition. However, for beams having non-compact flanges, the previously proposed equations produced over conservative results. Further study can also be made on stepped beams with varying degree of symmetries, loading conditions, boundary conditions and stepped beam parameters.

Sewage Pipe Renewal (SPR) method rehabilitate pipeline by forming a PVC profile inside the pipe by using a winding machine without excavating the soil above the pipe which lowers the cost of the rehabilitation. This study will investigate the effects of varying the pipe’s diameter to its wall thickness ratio. The dimensions for the diameter and minimum wall thickness of the non-reinforced concrete pipe will be based from ASTM C14. The finite element analysis software, ABAQUS, will be used to model and perform the analysis for the composite pipes. To account for the soil-pipe interaction, soil springs will be used as the bedding support to hold the pipe in place. Additionally, three soil types will be used to compare the behavior of the pipe with different diameter to thickness ratios. The results from the finite element analysis will be shown in tables and plotted into graphs and a concluding remarks will be provided.

This study focuses on the effects of load height on the inelastic lateral buckling of doubly stepped I-beams. The effects of having compact and non-compact flanges are also covered by this study. Two sections are analyzed: one having compact flanges and web while the other section has a compact web and non-compact flanges. The loadings are limited to those having an inflection point of zero. Also, the three main locations for the loads analyzed would be at the top of the flange, at the shear and at the bottom flange. The nonlinear analysis is done using the finite element program, ABAQUS. Also, to take into consideration the effect of inelastic buckling, residual stresses and geometric imperfections are applied to the models made. The results of the analysis would then determine if the location of the loads has significant effects on the buckling strength of the stepped beams. Also, the results are compared to the results of previous studies involving the effects of load-height on prismatic beams. The final results are tabulated and conclusions and new design methods are provided.

This study analyzes the buckling safety in the area of circumferentially edge-stiffened door openings without any additional longitudinal stiffeners of offshore tubular steel towers. The tubular steel tower is subjected to six (6) different load situations which are deemed to be normal and abnormal operating cases for the ultimate limit state. Analytical method using parametric equations based on Eurocode 3 - Design of Steel Structures and numerical method of finite element are used to analyze the critical meridional buckling stress. ABAQUS, a finite element program, is used for the numerical method analysis. Buckling safety analysis in the localized area near the opening is studied, and points of interest are defined for comparison between the two aforementioned analyses. Findings are tabulated and shown in illustrative charts, and conclusions are made.

This parametric study investigates the effect of significant parameters on the elastic global lateral torsional buckling capacity of horizontally curved twin I-girder systems. Included are the effect of curvature and the effect of girder spacing. Twin I-girder systems analyzed in this study are those which are interconnected by intermediate cross frames and are subjected to uniform moment. The finite element analysis software, ABAQUS, is used to model the horizontally curved twin I-girder system and conduct the buckling analysis. To see the significant effect of curvature and girder spacing, the results from the finite element analysis of horizontally curved twin I-girder systems are compared to the results of a closed form solution for straight twin I-girder systems. The findings of this parametric study will be shown using illustrative figures and tabulated data and conclusions are made.

This study was conducted to evaluate the control effect of fungicides on control of brown leaf blight, growth characteristics, and dry root yield in the cultivation of Alisma plantago after early maturing rice cropping. All fungicides treated had no effect on the growth and flowering rate of Alisma plantago. The major fungicides were mancozeb Wp, 75%, chlorothalonil Wp, 75%, dithianon Wp, 43%, difenoconazole Wp, 10%, benomyl Wp, 50%, and propineb Wp, 70%. Dry root of yield were increased largely with chlorothalonil Wp, 75%(33 g/20), fungicide than the other fungicides and control. All fungicides had no injury with standard dosage. On the other hand all fungicides had slight injury in the double dosage level for the Alisma plantago.