scholarly journals An investigation of strength degradation due to thickness plate reduction on Ferry Ro-Ro Ship’s Hull

2021 ◽  
Vol 921 (1) ◽  
pp. 012053
Author(s):  
A M Nugraha A ◽  
M U Pawara ◽  
A Ardianti ◽  
F Mahmuddin
Keyword(s):  
Structural Strength ◽  
Plate Thickness ◽  
Strength Degradation ◽  
Element Analysis ◽  
Allowable Limit ◽  
Strength Performance ◽  
Dimensional Changes ◽  
Longitudinal Response ◽  
Package Program ◽  
Shell Plate

Abstract Old ships will experience a degradation of the structural strength after receiving repeated loads. Decreased strength performance is also caused by structure shape and structural dimensions changes. In steel ships, Dimensional changes will be discovered when the ship is docked, because the material undergo corrosion causing in thinning the shell plate. In this study, a thickness reduction of the shell plate has been simulated to determine the longitudinal response of the ship’s structure. A Finite element analysis of ferry Ro-Ro ship’s hull was carried out using ANSYS package program. The simulation was carried out to exceed the allowable limit for reducing the thickness plate by the Indonesian Classification Bureau (BKI), which is 20% of the initial plate thickness. Based on simulation result, it was found that an increase of stress at each variation of the reduction in hull plate thickness in hogging and sagging conditions.

scholarly journals Numerical Analysis of Fire Water Storage Tank under Seismic Loading

2021 ◽  
Vol 850 (1) ◽  
pp. 012019
Author(s):  
R Nishanth ◽  
D Kishok Rai ◽  
Hemkar Sharma ◽  
Rivington Kingston ◽  
Davidson Jebaseelan ◽  
...  
Keyword(s):  
Finite Element ◽  
Storage Tank ◽  
Hoop Stress ◽  
Plate Thickness ◽  
Water Storage ◽  
Bottom Plate ◽  
Element Analysis ◽  
Water Storage Tank ◽  
Finite Element Analysis Simulation ◽  
Shell Plate

Abstract Maintenance and continuously monitoring the condition of above ground storage tanks are significant when the tanks are placed in service. The American Petroleum Institution (API) 653 and other international codes provides the minimum requirements for inspection & maintaining the integrity of tanks during its service. The tank settlement is one of the major threats for tank’s integrity. In this paper, a storage tank is assessed for uniform settlement under various loading condition such as seismic, dead load, static load, corrosion loss of shell plate etc. In the present study, a finite element model is designed with uniform settlement condition and study of its governing hoop stress at shell plate has been carried out under different loading conditions. A fire water storage tank (constructed with IS 2060 GR. B material) and different seismic zones in India are taken for this study. The finite element analysis simulation shows that increase of hoop stress in the bottom shell course due to uniform settlement, the decrease in plate thickness and with different seismic active regions. Moreover, the maximum stresses have been observed at shell bottom course (close to bottom plate).

Finite Element Analysis and Optimization of Long-Span Gantry NC Machining Center Structure

2011 ◽  
Vol 346 ◽  
pp. 379-384
Author(s):  
Shu Bo Xu ◽  
Yang Xi ◽  
Cai Nian Jing ◽  
Ke Ke Sun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Design Method ◽  
Dynamic Performance ◽  
Plate Thickness ◽  
Element Model ◽  
Wall Structure ◽  
Characteristic Analysis ◽  
Element Analysis ◽  
Dynamic Performance Analysis

The use of finite element theory and modal analysis theory, the structure of the machine static and dynamic performance analysis and prediction using optimal design method for optimization, the new machine to improve job performance, improve processing accuracy, shorten the development cycle and enhance the competitiveness of products is very important. Selected for three-dimensional CAD modeling software-UG NX4.0 and finite element analysis software-ANSYS to set up the structure of the beam finite element model, and then post on the overall structure of the static and dynamic characteristic analysis, on the basis of optimized static and dynamic performance is more superior double wall structure of the beam. And by changing the wall thickness and the thickness of the inner wall, as well as the reinforcement plate thickness overall sensitivity analysis shows that changes in these three parameters on the dynamic characteristics of post impact. Application of topology optimization methods, determine the optimal structure of the beam ultimately.

Integrated Optimization Design for a Radial Turbine Wheel of a 100kW-Class Microturbine

2011 ◽  
Author(s):  
Lei Fu ◽  
Yan Shi ◽  
Qinghua Deng ◽  
Huaizhi Li ◽  
Zhenping Feng
Keyword(s):  
Optimization Design ◽  
Design Method ◽  
Aerodynamic Performance ◽  
Original Design ◽  
Element Analysis ◽  
Turbine Wheel ◽  
Strength Performance ◽  
Integrated Optimization ◽  
Radial Turbine ◽  
Integrated Optimization Design

The aerodynamic performance, structural strength and wheel weight are three important factors in the design process of the radial turbine. This paper presents an investigation on these aspects and develops an optimization design approach for radial turbine with consideration of the three factors. The aerodynamic design for the turbine wheel with inlet diameter of 230mm for 100kW-class microturbine unit is carried out firstly as the original design. Then, the cylinder parabolic geometrical design method is applied to the wheel modeling and structural design, but the maximum stress predicted by Finite Element Analysis greatly exceeds the yield limit of material. Furthermore, the wheel weight is above 7.2kg thus bringing some critical difficulties for bearing design and turbine operation. Therefore, an integrated optimization design method for radial turbine is studied and developed in this paper with focus on the wheel design. Meridional profiles and shape lines of turbine wheel are optimized with consideration of the whole wheel weight. Main structural modeling parameters are reselected to reduce the wheel weight. Trade-off between aerodynamic performance and strength performance is highly emphasized during the optimization design. The results show that the optimized turbine wheel gets high aerodynamic performance and acceptable stress distribution with the weight less than 3.8kg.

Determination of Stress Concentration Around an Oblique Hole by a Finite-Element Technique

1983 ◽  
Vol 105 (2) ◽  
pp. 206-212 ◽  
Author(s):  
Hua-Ping Li ◽  
F. Ellyin
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Maximum Stress ◽  
Plate Thickness ◽  
Two Dimensional ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Parametric Studies ◽  
Element Technique

A plate weakened by an oblique penetration of a circular cylindrical hole has been investigated. The stress concentration around the hole is determined by a finite-element method. The results are compared with experimental data and other analytical works. Parametric studies of effects of angle of inclination, plate thickness, and width are performed. The maximum stress concentration factor (SCF) obtained from the finite-element analysis is higher than experimental results, and this deviation increases with the increase of angle of skewness. The major reason for this difference is attributed to the shear-action between layers parallel to the plate surface which cannot be directly included in the two-dimensional elements. An empirical formula is derived which accounts for the shear-action and renders the finite-element predictions in line with experimentally observed data.

Flexural Behavior Finite Element Analysis of CFRP Reinforced Concrete Bridge Deck with Corrosion and Salt Resistance

2014 ◽  
Vol 1004-1005 ◽  
pp. 1474-1477
Author(s):  
Ze Ying Yang ◽  
Jia You Liu ◽  
Yi Dong Zhang ◽  
Jian Bo Qu
Keyword(s):  
Numerical Simulation ◽  
Reinforced Concrete ◽  
Bridge Deck ◽  
Flexural Behavior ◽  
Concrete Bridge ◽  
Element Analysis ◽  
Strength Performance ◽  
Reinforced Concrete Bridge ◽  
Concrete Bridge Deck ◽  
Prestressed Structures

By numerical simulation and contrasting with experimental conclusions, mechanical models in every loading stage of CFRP reinforced concrete bridge deck were established. The results showed that, numerical simulation results of non-prestressed bridge decks fitted corresponding test results well. The stiffness of prestressed structures had been greatly improved than non-prestressed structures, so the high strength performance of CFRP had been used more effectively.

Comparative Design of Orthogonally Stiffened Plates for Production and Structural Integrity—Part 1: Size Optimization

1994 ◽  
Vol 10 (03) ◽  
pp. 146-155
Author(s):  
Nicholas Hatzidakis ◽  
Michael M. Bernitsas
Keyword(s):  
Structural Integrity ◽  
Plate Theory ◽  
Plate Thickness ◽  
Stiffened Plates ◽  
Size Optimization ◽  
Element Analysis ◽  
Total Cost ◽  
Plate Buckling ◽  
Design Variables ◽  
Overall Buckling

Five alternative configurations of orthogonally stiffened plates are compared in order to identify the total cost optimum design including material and fabrication cost. Size optimization is performed within the limitations of structural component standardization for each of the five alternatives. The five optimal structures are then compared in terms of weight, fabrication, and total cost. Discrete sizing optimization is performed in this paper with two design variables, i.e., plate thickness and standardized beam cross section. Constraints are imposed on secondary and tertiary stresses computed by finite-element analysis (FEA); and on primary stresses to prevent plate buckling, stiffener tripping, and overall buckling. Confidence is established in the FEA results by making comparisons with FEA results using the effective breadth method and orthotropic plate theory. Producibility constraints dictated by standardization in shipyard practice are imposed as well.

Analysis of Three-Dimensional Clamped Single Edge Notched Tension (SENT) Specimens

2018 ◽  
Author(s):  
Zheng Liu ◽  
Xu Chen ◽  
Xin Wang
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Crack Depth ◽  
Plate Thickness ◽  
Three Dimensional ◽  
Width Ratio ◽  
Element Analysis ◽  
Out Of Plane ◽  
T Stress

In the present paper, three-dimensional clamped SENT specimens, which is one of the most widely used low-constraint and less-conservative specimen, are analyzed by using a crack compliance analysis approach and extensive finite element analysis. Considering the test standard (BS8571) recommended specimen sizes, the daylight to width ratio, H/W, is 10.0, the relative crack depth, a/W, is varied by 0.2, 0.3, 0.4, 0.5 or 0.6 and the relative plate thickness, B/W, is chosen by 1.0, 2.0 or 4.0, respectively. Complete solutions of fracture mechanics parameters, including stress intensity factor (K), in-plane T-stress (T11) and out-of-plane T-stress (T33) are calculated, and the results obtained from above two methods have a good agreement. Moreover, the combination of the effects of a/W and B/W on the stress intensity factor K, T11 and T33 stress are thus illustrated.

On the Interaction of Non-Coplanar Embedded Crack With Surface Crack in 3D Using FE and Multi-Level Sub-Structuring

2002 ◽  
Author(s):  
Walied A. Moussa
Keyword(s):  
Surface Crack ◽  
Crack Depth ◽  
Plate Thickness ◽  
Three Dimensional ◽  
Infinite Plate ◽  
Separation Distance ◽  
Multiple Cracks ◽  
Element Analysis ◽  
Weld Toe ◽  
Embedded Crack

The interaction and coalescence of multiple cracks may significantly affect the designed lives of aging pressure vessel structures. Knowledge of the growth behavior of interacting cracks is still limited. In this paper, a novel sub-modeling meshing algorithm is used in three-dimensional linear finite element analysis to investigate the interaction between two identical, non-coplanar, semi-elliptical cracks. One of these cracks is modeled as a surface crack while the other is modeled as an embedded crack under a weld toe. Both interacting cracks are assumed to be in an infinite plate subjected to a remote tension loading condition. The energy release rates (G) and the Stress Intensity Factors (SIF’s) for these cracks are calculated along the interacting crack-front. And, a parametric study involving the variation of the relative horizontal separation distance between the two interacting cracks is carried out for a specific crack depth to plate thickness ratio, a/t, of 0.2. The crack shape aspect ratio, a/c, is also varied in this study within a range that extend between 1.0 and 0.33. An empirical formula is derived that relates the effects of the relative positions of these cracks to their SIFs.

Sign in / Sign up

Export Citation Format

Share Document