Optimal pile design of dolphin structure considering axial compressive pressure-bending moment ratio under offshore load conditions

2018 ◽  
Vol 233 (4) ◽  
pp. 1141-1153
Author(s):  
Hailong Shao ◽  
Jongsoo Lee
Keyword(s):  
Optimal Solution ◽  
Bending Moment ◽  
Analysis Data ◽  
Total Weight ◽  
Surface Model ◽  
Total Displacement ◽  
Moment Ratio ◽  
Steel Piles ◽  
Compressive Pressure ◽  
Load Conditions

This study proposes an optimal design of a dolphin structure under offshore load conditions such as berthing, mooring, wind, wave, and current loads. The design objective is to reduce the total weight of the pile structure by determining its diameter, thickness, and arraying direction with constraints of axial compressive pressure-bending moment ratio and total displacement. As design requirements, the stress has to be satisfied under the allowable compressive pressure-bending moment, and the total displacement of the steel piles should be less than 0.1 m on the upper deck. The structural analysis data are generated using Box–Behnken design based on the design of experiments. In the meta-model-based approximate optimization process, the pressure-bending moment ratio and total displacement are expressed using a backpropagation neural network, and the structural weight of the pile is approximated via a second-order polynomial-based response surface model. Compared with the initial design, the optimal solution of the total weight of the steel piles reduces by 27.37% under the satisfied constraint conditions. For the post-optimization study, the optimal sensitivity analysis with respect to the seabed level is conducted.

THE INFLUENCE OF SEX HORMONES ON THE BONY CHANGES OCCURRING IN PARALYSED LIMBS

1954 ◽  
Vol 11 (1) ◽  
pp. 66-70 ◽  
Author(s):  
J. A. GILLESPIE
Keyword(s):  
Young’S Modulus ◽  
Sex Hormones ◽  
Modulus Of Elasticity ◽  
Young's Modulus ◽  
Bending Moment ◽  
Breaking Point ◽  
Total Weight ◽  
Breaking Stress ◽  
Young’S Modulus Of Elasticity ◽  
Ash Weight

SUMMARY 1. Paralysis, produced in young male rats by avulsion of peripheral nerves, resulted in a highly significant reduction in the total weight, ash weight, ash percentage, X-ray density and bending moment at the breaking point, of the bones of the affected limb. The breaking stress was significantly reduced, but Young's modulus of elasticity was unaltered. 2. Certain of these changes were modified by treatment with sex hormones. Both oestradiol and testosterone significantly reduced the difference between the bones of the normal and paralysed limbs in respect of total weight, ash weight and bending moment at the breaking point. 3. Treatment with oestradiol significantly increased both the ash percentage and Young's modulus of elasticity, the increase affecting equally the bones of the normal and paralysed limbs. Testosterone treatment did not significantly affect either of these properties, and neither hormone affected the breaking stress.

Structural Behavior of Umbilicals: Part II—Model-Experimental Comparisons

2010 ◽  
Author(s):  
Celso Pupo Pesce ◽  
Andre´ Lui´s Condino Fujarra ◽  
Marcos Rabelo ◽  
Rafael Loureiro Tanaka ◽  
Clo´vis de Arruda Martins ◽  
...  
Keyword(s):  
External Surface ◽  
Bending Moment ◽  
Steel Tube ◽  
Strain Gages ◽  
Pressure Loading ◽  
Outer Sheath ◽  
Tension Tests ◽  
Variable Tension ◽  
Load Conditions ◽  
Experimental Comparisons

A set of tests was performed in a non-armored Steel Tube Umbilical (STU), including pure pressure loading, constant and variable tension loads and combinations of constant and cyclic bending moment and tension. Tests were made for pressurized and non pressurized conditions. Strains were measured with strain gages attached to the external surface of selected tubes. Instrumentation was performed in four windows that were opened on the umbilical outer sheath to provide access to the tubes. Besides the strains, tension, internal pressure and imposed angle were measured. Comparisons with results obtained using the model presented in Part I, [1], are presented for different load conditions.

Evaluation of Temperature Simulation over Northern Thailand from Regional Climate Model Coupled with Land Surface Model

2017 ◽  
Vol 866 ◽  
pp. 108-111
Author(s):  
Theerapan Saesong ◽  
Pakpoom Ratjiranukool ◽  
Sujittra Ratjiranukool
Keyword(s):  
Regional Climate Model ◽  
Land Surface ◽  
Climate Model ◽  
Global Analysis ◽  
Regional Climate ◽  
Land Surface Model ◽  
Analysis Data ◽  
Surface Model ◽  
Northern Thailand ◽  
Weather Model

Numerical Weather Model called The Weather Research and Forecasting model, WRF, developed by National Center for Atmospheric Research (NCAR) is adapted to be regional climate model. The model is run to perform the daily mean air surface temperatures over northern Thailand in 2010. Boundery dataset provided by National Centers for Environmental Prediction, NCEP FNL, (Final) Operational Global Analysis data which are on 10 x 10. The simulated temperatures by WRF with four land surface options, i.e., no land surface scheme (option 0), thermal diffusion (option 1), Noah land-surface (option 2) and RUC land-surface (option 3) were compared against observational data from Thai Meteorological Department (TMD). Preliminary analysis indicated WRF simulations with Noah scheme were able to reproduce the most reliable daily mean temperatures over northern Thailand.

Analysis and optimization of morphing wing aerodynamics

2019 ◽  
Vol 91 (3) ◽  
pp. 538-546 ◽  
Author(s):  
Witold Artur Klimczyk ◽  
Zdobyslaw Jan Goraj
Keyword(s):  
Optimal Solution ◽  
Design Sensitivity ◽  
Substantial Improvement ◽  
Surface Model ◽  
Morphing Wing ◽  
Trailing Edge ◽  
Significant Information ◽  
Content Type ◽  
Additional Information ◽  
Wing Optimization

PurposeThe purpose of this paper is to present a method for analysis and optimization of morphing wing. Moreover, a numerical advantage of morphing airfoil wing, typically assessed in simplified two-dimensional analysis is found using higher fidelity methods.Design/methodology/approachBecause of multi-point nature of morphing wing optimization, an approach for optimization by analysis is presented. Starting from naïve parametrization, multi-fidelity aerodynamic data are used to construct response surface model. From the model, many significant information are extracted related to parameters effect on objective; hence, design sensitivity and, ultimately, optimal solution can be found.FindingsThe method was tested on benchmark problem, with some easy-to-predict results. All of them were confirmed, along with additional information on morphing trailing edge wings. It was found that wing with morphing trailing edge has around 10 per cent lower drag for the same lift requirement when compared to conventional design.Practical implicationsIt is demonstrated that providing a smooth surface on wing gives substantial improvement in multi-purpose aircrafts. Details on how this is achieved are described. The metodology and results presented in current paper can be used in further development of morphing wing.Originality/valueMost of literature describing morphing airfoil design, optimization or calculations, performs only 2D analysis. Furthermore, the comparison is often based on low-fidelity aerodynamic models. This paper uses 3D, multi-fidelity aerodynamic models. The results confirm that this approach reveals information unavailable with simplified models.

scholarly journals Comparison of Dynamic Programming Algorithm and Greedy Algorithm on Integer Knapsack Problem in Freight Transportation

2018 ◽  
Vol 5 (1) ◽  
pp. 49 ◽  
Author(s):  
Global Ilham Sampurno ◽  
Endang Sugiharti ◽  
Alamsyah Alamsyah
Keyword(s):  
Dynamic Programming ◽  
Greedy Algorithm ◽  
Knapsack Problem ◽  
Dynamic Programming Algorithm ◽  
Optimal Solution ◽  
Freight Transportation ◽  
Total Weight ◽  
Knapsack Problems ◽  
Programming Algorithm ◽  
Selection Of

At this time the delivery of goods to be familiar because the use of delivery of goods services greatly facilitate customers. PT Post Indonesia is one of the delivery of goods. On the delivery of goods, we often encounter the selection of goods which entered first into the transportation and  held from the delivery. At the time of the selection, there are Knapsack problems that require optimal selection of solutions. Knapsack is a place used as a means of storing or inserting an object. The purpose of this research is to know how to get optimal solution result in solving Integer Knapsack problem on freight transportation by using Dynamic Programming Algorithm and Greedy Algorithm at PT Post Indonesia Semarang. This also knowing the results of the implementation of Greedy Algorithm with Dynamic Programming Algorithm on Integer Knapsack problems on the selection of goods transport in PT Post Indonesia Semarang by applying on the mobile application. The results of this research are made from the results obtained by the Dynamic Programming Algorithm with total weight 5022 kg in 7 days. While the calculation result obtained by Greedy Algorithm, that is total weight of delivery equal to 4496 kg in 7 days. It can be concluded that the calculation results obtained by Dynamic Programming Algorithm in 7 days has a total weight of 526 kg is greater when compared with Greedy Algorithm.

scholarly journals Optimal Modelling of Steel Multi-Span Beams Using the Gradient-Iterative Method

2019 ◽  
Vol 29 (4) ◽  
pp. 112-127
Author(s):  
Leszek Mikulski
Keyword(s):  
Iterative Method ◽  
Optimal Solution ◽  
Optimization Method ◽  
Iterative Optimization ◽  
Basic Assumptions ◽  
The Web ◽  
Load Conditions

Abstract The article describes the gradient-iterative optimization method and outlines the method’s basic assumptions and illustrates its general use. The method’s implementation was illustrated based on a steel I-beam. The described calculation example concerns the optimization of the height of the web of a multi-span beam. The method enables finding an optimal solution with the use of simple and commonly available software. To illustrate the effectiveness of the optimization method, multiple calculations were performed for beams with various spans and various load conditions.

Probabilistic Analysis of Gun Barrel Ablation Life Based on the Modified Response Surface Model

2014 ◽  
Vol 1004-1005 ◽  
pp. 1076-1083 ◽  
Author(s):  
Wei Zhou ◽  
Jun Fang
Keyword(s):  
Response Surface ◽  
Estimation Error ◽  
Optimal Solution ◽  
Solution Space ◽  
Response Surface Model ◽  
Parameters Estimation ◽  
Surface Model ◽  
Gun Barrel ◽  
Stochastic Fem ◽  
Low Efficiency

The randomness of structural and material parameters needs to be considered in the reliability analysis of gun barrel ablation life. However, the traditional method, like Stochastic FEM sampling, results in huge computing workload and low efficiency. This paper proposed a modified response surface model for estimating the gun barrel ablation life. In which, the estimation error of the response surface model is the optimization goal. Gauss-Newton method (GNM) is used to get the optimal solution whose initial value is solved by Genetic-algorithm (GA). After that, ablation life can be calculated by the optimized response surface model. GA is effective in global solution space searching, while GNM is effective in local searching. The new method takes full advantages of both GA and GNM in parameters estimation. The simulation result shows that the combination of GA and GNM obtains a higher precision of ablation estimation and greatly improves the computational efficiency.

Structural Morphogenesis for RC Free-Form Surface Shell with Arbitrary Boundary Shape And Opening - Comparison of Optimal Solution and Application of Decent Solutions Search Method

2021 ◽  
Vol 62 (2) ◽  
pp. 113-123
Author(s):  
Kodai Nagata ◽  
Toshio Honma
Keyword(s):  
Optimal Solution ◽  
Bending Moment ◽  
Search Method ◽  
Free Form ◽  
Shell Shape ◽  
Arbitrary Boundary ◽  
Boundary Shape ◽  
Bee Colony ◽  
Surface Shell ◽  
Free Form Surface

In this paper, artificial bee colony (ABC) to obtain the decent solutions that the authors proposed is applied to the structural morphogenesis for RC (Reinforced-Concrete) free-form surface shell with arbitrary boundary shape. The 'decent solutions' have relatively high evaluation solutions that maintain the diversity of the design variable space, including the global optimal solution and local optimal solutions. In this paper, we focus on an opening of RC free form surface shell structures considering design and functionality, and the structural morphogenesis procedure that considers constraints of the excessive bending moment caused by the presence of an opening in the shell is proposed. Numerical results demonstrate the efficacy of a structural morphogenesis procedure that simultaneously considers shell shape, thickness, and opening as design variables. Furthermore, it is shown that proposed structural morphogenesis using decent solutions search method can support a designer's idea of architectural forms having a relationship between shape and mechanical behavior at the initial stage of design.

Fuzzy Heuristic Gradient Projection for Frame Topology Optimization

2005 ◽  
Author(s):  
Mohamed S. Senousy ◽  
Hesham A. Hegazi ◽  
Sayed M. Metwalli
Keyword(s):  
Fuzzy Logic ◽  
Fuzzy Logic Controller ◽  
Axial Stress ◽  
Equivalent Stress ◽  
Optimal Solution ◽  
Bending Moment ◽  
Gradient Projection ◽  
Bending Stress ◽  
Allowable Stress ◽  
Bending Stresses

In this paper, a new methodology to obtain an optimal structure size considering geometries nonlinearity is presented. This method makes use of Heuristic Gradient Projection method in addition to Fuzzy Logic. The Heuristic Gradient Projection (HGP) method, a previously developed method for 3D-frame design and optimization, utilizes mainly bending stress relations in order to simplify the process of iterations. HGP is based on comparing the resulting equivalent stress with the allowable stress value. The proposed Fuzzy Heuristic Gradient Projection (FHGP) approach incorporates both bending stress and axial stress when processing with the allowable stress value. The weighting factors of both axial and bending stresses are found using a Fuzzy Logic controller. Fuzzy logic is incorporated to reach an optimal solution with lesser number of function evaluations. A simple cantilever example, subjected to axial force and bending moment, is presented to illustrate this approach in addition to a 10-member planar frame that is used to prove the efficacy of the new method. FHGP approach generally results in faster convergence.

Research on Precast Roof Truss of Prestressed Concrete Square Pile

2014 ◽  
Vol 488-489 ◽  
pp. 359-364
Author(s):  
Jia Bin Liu ◽  
Zheng Xing Guo ◽  
Le Qi Chen
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Prestressed Concrete ◽  
Control Method ◽  
Optimal Solution ◽  
Bending Moment ◽  
Scale Model ◽  
Element Analysis ◽  
Design Load ◽  
Roof Truss

The precast roof truss of prestressed concrete square pile is a new self-balancing system composed of prestressed concrete square pile, strut and steel tension rod. Based on finite element analysis methods, the bending moment and deformation under most unfavorable design load was checked upon crack resistant bending moment to verify its engineering feasibility, the optimal prestressed value was analyzed to get the camber of the top chord beam, and the optimal tension method for bottom chord tension rod was determined. Compared with finite element analysis results, the full scale model test was carried out to further verify its engineering feasibility and some optimization recommendation was proposed. It suggests that the tension order of middle section before diagonal rod, initial prestressed value of 10t, and prestressed control method of monitoring camber at midspan is the most reasonable and optimal solution.

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