The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
Muhammad Hidayat Arif - One of the best experts on this subject based on the ideXlab platform.
-
Analysis of Corrugated Bulkhead Against Transverse Plane Bulkhead in a Tanker Ship
EPI International Journal of Engineering, 2018Co-Authors: Hamzah Hamzah, Ganding Sitepu, Muhammad Hidayat ArifAbstract:Ship is built from thousands of integrated construction materials. The selection of a strong and efficient construction material is significant since it directly affects the weight of the ship. For a watertight Bulkhead in a tanker ship, there are two kinds of Bulkhead construction which are transverse plane Bulkhead and corrugated Bulkhead. The selection of these two Bulkhead constructions for watertight Bulkhead is based on the Bulkhead strength analysis as well as Bulkhead weight. The analysis was conducted using an engineering structural analysis software by comparing the Bulkhead structural configurations which has the same von Misses tension. For corrugated Bulkhead, corrugation angle was simulated between 45°- 90° while for transverse plane Bulkhead, the range of stiffener distances was simulated between 400-1400 mm. The result shows that minimum corrugated Bulkhead weight which is 41.18 ton can be obtained on the corrugation angle of 60o with the structural efficiency ratio of 1.79% - 30.91% while for transverse plane Bulkhead, minimum weight of Bulkhead which is 71.175 ton can be obtained on the stiffeners distance of 600 mm with structural efficiency ratio of 2.62% - 60.25%. It can be seen that for the same von Misses tension, corrugated Bulkhead construction is more efficient in terms of Bulkhead weight and cost with the difference weights of almost 30 ton.
Il Yong Kim - One of the best experts on this subject based on the ideXlab platform.
-
Topology optimization of a pre-stiffened aircraft Bulkhead
Structural and Multidisciplinary Optimization, 2019Co-Authors: Braden T. Warwick, Chris K Mechefske, Il Yong KimAbstract:The Bulkhead of an aft-fuselage twin-engine mounted aircraft is a pivotal structural component from a noise and vibrations perspective as it is the main transmission path for the engine-induced vibration to propagate into the passenger cabin. Despite this, there has yet to be a successful implementation of topology optimization (TO) on a pre-stiffened aircraft Bulkhead. This work is the first to investigate TO on a pre-stiffened Bulkhead with a frequency-based problem statement. The objective function was set to maximize the first eigenfrequency to maximize the stiffness to mass ratio of the Bulkhead. Frequency constraints were implemented to eliminate the natural frequencies within range of the engine excitation frequency. A volume fraction constraint was set such that the mass of the solution was less than the mass of similar Bulkhead stiffeners reported in the literature. The first successful implementation of topology optimization on a pre-stiffened aircraft Bulkhead was obtained. Two designs satisfying the optimality criterion were generated, both of which were able to improve Bulkhead structural integrity, reduce mass, and eliminate resonance from ± 10% of the engine excitation frequency. This work demonstrates that TO is a useful tool to help aerospace engineers improve the vibro-acoustic properties of the Bulkhead without sacrificing mass or structural integrity. The methodology introduced in this work can be easily integrated into aircraft design, as it uses tools widely available in the aerospace industry.
-
Effect of Stiffener Configuration on Bulkhead Modal Parameters
Volume 8: 30th Conference on Mechanical Vibration and Noise, 2018Co-Authors: Braden T. Warwick, Chris K Mechefske, Il Yong KimAbstract:Optimization of Bulkhead stiffener configuration has been an active area of research over the past decade, but no real practical solutions have been generated. This research investigates Bulkhead stiffener configuration on a rudimentary level, by analyzing the modal parameters of three different stiffener configurations. Experimental data was used to validate the computational models of two modified Bulkhead stiffener configurations. Operational boundary conditions were then applied to the computational models to assess the modal density of the modified Bulkheads within the aircraft engine rotational frequency range. Removal of one horizontal stiffener reduced the overall stiffener mass by 12.2% without generating any modes within 4% of the engine rotational frequency. The inconsistencies of natural frequency changes due to stiffener configuration highlights the difficulty with applying generalized optimization approaches without a thorough understanding of the modes of interest. The results of this work suggest that the fundamental analysis performed herein is necessary to generate a complete understanding of the modal parameters of the Bulkhead prior to performing in-depth optimization work.
Sang-hoon Shin - One of the best experts on this subject based on the ideXlab platform.
-
A study on minimum weight design of vertical corrugated Bulkheads for chemical tankers
Elsevier, 2018Co-Authors: Sang-hoon ShinAbstract:Corrugated Bulkhead has been adopted for cargo tank Bulkheads of commercial vessels such as bulk carriers, product oil carriers and chemical tankers. It is considered that corrugated Bulkhead is a preferred structural solution, compared to the flat stiffened Bulkhead, due to several advantages such as lower mass, easier maintenance and smaller corrosion problems. Many researches to find the optimum shape of corrugated Bulkhead have been mostly carried out for bulk carriers. Compared to corrugated Bulkheads of bulk carriers, ones of chemical tankers are more complicated since they are composed of transverse and longitudinal Bulkheads, and they are made of higher priced materials. The purpose of this study is the development of minimum weight design method for corrugated Bulkhead of chemical tankers. Evolution strategy is applied as an optimization technique. It has been verified from many researches that evolution strategy searches global optimum point prominently by using multi-individual searching technique. Multi-individual searching methods need excessive time if they connect to 3-D finite element model for repetitive structural analyses. In order to resolve this issue, 2-D beam element connected to deck and lower stool is substituted for a corrugated structure in this study. To verify the reliability of the structural responses by idealized 2-D beam model, they have been compared with ones by 3-D finite element model. In this study, optimum design for corrugated Bulkhead of 30 K chemical tanker has been carried out, and the results by developed optimum design program have been compared with design data of existing ship. It is found out that optimum design is about 9% lighter than one of existing ship. Keywords: Corrugated Bulkheads, Chemical tankers, Minimum weight design, Generalized slope deflection method, Evolution strateg
-
A Study on the Optimum Design of Corrugated Bulkhead for Product Carrier
IOP Conference Series: Materials Science and Engineering, 2017Co-Authors: Sang-hoon ShinAbstract:For a product carrier, in general, longitudinal Bulkhead as well as transverse Bulkhead is corrugated type and the intersection part of Bulkheads is utilized for a pipe trunk. Since lower and upper stools are to be connected with all of longitudinal and transverse Bulkheads, they have a uniform height respectively. The purpose of this study is the development of design technique for the minimization of total weight of longitudinal and transverse Bulkheads at the initial design stage. In this study, optimum design of corrugated Bulkhead for product carrier was conducted by applying evolution strategy method (ESM) as an optimization method and beam elements based on generalized slope deflection method (GSDM) in structural analysis. Furthermore, the installations of pipe trunks and the interference of stool diaphragms and brackets were considered to conform to the actual ship design. The optimization results are compared with the existing 70K product carrier designed in accordance with the DNV classification requirements and showed about 3% reduction in weight.
-
A study on minimum weight design of vertical corrugated Bulkheads for chemical tankers
International Journal of Naval Architecture and Ocean Engineering, 2017Co-Authors: Sang-hoon Shin, Dae-eun KoAbstract:Abstract Corrugated Bulkhead has been adopted for cargo tank Bulkheads of commercial vessels such as bulk carriers, product oil carriers and chemical tankers. It is considered that corrugated Bulkhead is a preferred structural solution, compared to the flat stiffened Bulkhead, due to several advantages such as lower mass, easier maintenance and smaller corrosion problems. Many researches to find the optimum shape of corrugated Bulkhead have been mostly carried out for bulk carriers. Compared to corrugated Bulkheads of bulk carriers, ones of chemical tankers are more complicated since they are composed of transverse and longitudinal Bulkheads, and they are made of higher priced materials. The purpose of this study is the development of minimum weight design method for corrugated Bulkhead of chemical tankers. Evolution strategy is applied as an optimization technique. It has been verified from many researches that evolution strategy searches global optimum point prominently by using multi-individual searching technique. Multi-individual searching methods need excessive time if they connect to 3-D finite element model for repetitive structural analyses. In order to resolve this issue, 2-D beam element connected to deck and lower stool is substituted for a corrugated structure in this study. To verify the reliability of the structural responses by idealized 2-D beam model, they have been compared with ones by 3-D finite element model. In this study, optimum design for corrugated Bulkhead of 30 K chemical tanker has been carried out, and the results by developed optimum design program have been compared with design data of existing ship. It is found out that optimum design is about 9% lighter than one of existing ship.
Xia Qi-qian - One of the best experts on this subject based on the ideXlab platform.
-
Effect of Bulkhead vibration on vibro-acoustic characteristics of ring-stiffened cylindrical shell
Journal of Naval University of Engineering, 2014Co-Authors: Xia Qi-qianAbstract:Bulkhead vibration can influence the vibro-acoustic characteristics of ring-stiffened cylindrical shell.For this reason,FEM/BEM is used for the numerical calculation of the vibro-acoustic characteristics according to the Bulkhead boundary condition and structure parametric change.And analyses are made of the influences of the constrained condition,cabin sectional dimension,shape,thickness and stiffened rib of the Bulkhead respectively.The results show that the simple supporting boundary is available for the research of cylindrical shell vibration and sound radiation.Cabin sectioning has great influence on the vibro-acoustic characteristics of cylindrical shell.Changing the Bulkhead′s shape could influence the mean square vibration velocity amplitude.The effect of thickening the Bulkhead and adding stiffened rib to the Bulkhead on the vibro-acoustic characteristics of cylindrical shell should be taken into account according to the frequency range.In general,all this is useful for improving the vibro-acoustic characteristics of cabins.
-
Analysis of Cabin’s Vibro-acoustic Characteristics and Control of Bulkhead Vibration
Noise and Vibration Control, 2014Co-Authors: Xia Qi-qianAbstract:In order to depress the effect of Bulkhead vibration on cabin's vibro-acoustic characteristics, structural-acoustic design of Bulkhead is done. According to the theory of damping vibration attenuation, the Bulkhead is coated with a viscoelastic layer for reducing the vibration response. As to increase transmission loss, a back annular plate is attached between the Bulkhead and the shell according to the principle of impedance mismatch. The vibro-acoustic characteristics of the cabin are calculated by FEM/BEM and the Bulkhead's vibration control effect is analyzed. The results show that Bulkhead coated with the viscoelastic layer and added with the attached back annular plate can not only reduce cabin's vibration and sound radiation effectively, but also isolate the structure-borne sound from the adjacent cabin significantly. So, this is a better measure for Bulkhead's vibration damping and noise reduction.
Hamzah Hamzah - One of the best experts on this subject based on the ideXlab platform.
-
Analysis of Corrugated Bulkhead Against Transverse Plane Bulkhead in a Tanker Ship
EPI International Journal of Engineering, 2018Co-Authors: Hamzah Hamzah, Ganding Sitepu, Muhammad Hidayat ArifAbstract:Ship is built from thousands of integrated construction materials. The selection of a strong and efficient construction material is significant since it directly affects the weight of the ship. For a watertight Bulkhead in a tanker ship, there are two kinds of Bulkhead construction which are transverse plane Bulkhead and corrugated Bulkhead. The selection of these two Bulkhead constructions for watertight Bulkhead is based on the Bulkhead strength analysis as well as Bulkhead weight. The analysis was conducted using an engineering structural analysis software by comparing the Bulkhead structural configurations which has the same von Misses tension. For corrugated Bulkhead, corrugation angle was simulated between 45°- 90° while for transverse plane Bulkhead, the range of stiffener distances was simulated between 400-1400 mm. The result shows that minimum corrugated Bulkhead weight which is 41.18 ton can be obtained on the corrugation angle of 60o with the structural efficiency ratio of 1.79% - 30.91% while for transverse plane Bulkhead, minimum weight of Bulkhead which is 71.175 ton can be obtained on the stiffeners distance of 600 mm with structural efficiency ratio of 2.62% - 60.25%. It can be seen that for the same von Misses tension, corrugated Bulkhead construction is more efficient in terms of Bulkhead weight and cost with the difference weights of almost 30 ton.
