Numerical analysis of the effect of composite repair on composite pipe structural integrity

2008 ◽  
pp. 39-48
Keyword(s):  
Numerical Analysis ◽  
Structural Integrity ◽  
Composite Repair ◽  
Composite Pipe

Design and topological optimization of rear pressure bulkhead for a typical aircraft

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Marshal Thakran ◽  
Meenakshi ◽  
Jitender Sharma ◽  
Charles Gilbert Martin
Keyword(s):  
Numerical Analysis ◽  
Significant Influence ◽  
Design Methodology ◽  
Structural Integrity ◽  
Topological Optimization ◽  
Content Type ◽  
Iterative Design ◽  
Practical Implications ◽  
Insight Into ◽  
Selection Of

Purpose The purpose of this paper is to evaluate the model of a rear pressure bulkhead with different design optimizations to meet the pressurized cabin requirements of an aircraft. Design/methodology/approach This paper presents the results of the static analysis of a dome-shaped rear pressure bulkhead model designed in Catia-v5. Numerical analysis of model meshed in hyper-mesh and solved using Opti-Struct for iterative design optimizations. Findings All the iterative models are analyzed at 9 Psi. Rear pressure bulkhead designed with L-section stringer shows better results than the model optimized with T-section stringer for the same thickness. The model optimized with L-shaped stinger also reduces the weight of the bulkhead without affecting the structural integrity. Practical implications It has been concluded in this paper that the selection of specific shapes of the stringers shows a significant influence on weight reduction. Originality/value This paper provides a topical, technical insight into the design and development of a rear pressure bulkhead. It also outlines the future development of dome-shaped rear pressure bulkhead.

scholarly journals Fish Cells, a new zero Poisson’s ratio metamaterial—Part I: Design and experiment

2020 ◽  
Vol 31 (13) ◽  
pp. 1617-1637
Author(s):  
Mohammad Naghavi Zadeh ◽  
Iman Dayyani ◽  
Mehdi Yasaee
Keyword(s):  
Numerical Analysis ◽  
Numerical Model ◽  
Poisson’S Ratio ◽  
Structural Integrity ◽  
Structural Response ◽  
Poisson's Ratio ◽  
Experimental Investigations ◽  
Fish Cells ◽  
Force Displacement ◽  
Model Approach

A novel cellular mechanical metamaterial called Fish Cells that exhibits zero Poisson’s ratio in both orthogonal in-plane directions is proposed. Homogenization study on the Fish Cells tessellation is conducted and substantially zero Poisson’s ratio behavior in a homogenized tessellation is shown by numerical analysis. Experimental investigations are performed to validate the zero Poisson’s ratio feature of the metamaterial and obtain force–displacement response of the metamaterial in elastic and plastic zone. A detailed discussion about the effect of the numerical model approach and joints on the structural response of the metamaterial is presented. Morphing skin is a potential application for Fish Cells metamaterial because of the integration benefits of zero Poisson’s ratio design. The structural integrity of the Fish Cells is investigated by studying the stiffness augmentation under tension and in presence of constraints on transverse edges. Finally, geometrical enhancements for improved integrity of the Fish Cells are presented that result in substantially zero stiffness augmentation required for morphing skins.

Numerical analysis of the performances of bonded composite repair with two adhesive bands in aircraft structures

2008 ◽  
Vol 82 (1) ◽  
pp. 84-89 ◽  
Author(s):  
H. Fekirini ◽  
B. Bachir Bouiadjra ◽  
M. Belhouari ◽  
B. Boutabout ◽  
B. Serier
Keyword(s):  
Numerical Analysis ◽  
Composite Repair ◽  
Aircraft Structures ◽  
Bonded Composite

Numerical Analysis of Residual Stresses in Hyperbaric Welding

2012 ◽  
Author(s):  
Xiaobo Ren ◽  
Odd M. Akselsen ◽  
Sigmund K. Ås ◽  
Bård Nyhus
Keyword(s):  
Residual Stress ◽  
Numerical Analysis ◽  
Residual Stresses ◽  
Pressure Range ◽  
Structural Integrity ◽  
Sea Water ◽  
Welding Residual Stress ◽  
Transformation Plasticity ◽  
Micro Structure ◽  
Welding Procedure

Hyperbaric welding residual stress is one of the main concerns for deep water operation. This study presents the numerical investigation of residual stresses in hyperbaric welding by using WeldsimS code. The pressure range investigated in this study is from 3 to 35 bar, which corresponds to 30 to 350 msw (Meters of Sea Water). Experiments results indicate that the welding procedure might be significantly influenced within the pressure range studied. A 2D axisymmetric model has been considered in this study to simulate circumferential welding of a pipe. Phase transformations and transformation plasticity during the welding procedure have been taken into account. The main aim of the study is to predict the hyperbaric welding residual stresses. The temperature evolution and the micro-structure were also studied. Results show that residual stresses induced by hyperbaric welding are significant within the pressure range investigated, which should be assessed for the sake of structural integrity.

Numerical Analysis of KI of Semi-Elliptical Surface Crack in Steel Structure Strengthened with FRP under Tensile Load

2011 ◽  
Vol 137 ◽  
pp. 42-49 ◽  
Author(s):  
Chuan Yu Zhao ◽  
Pei Yan Huang ◽  
Hao Zhou ◽  
Xiao Hong Zheng
Keyword(s):  
Numerical Analysis ◽  
Surface Crack ◽  
Structural Integrity ◽  
Tensile Load ◽  
Steel Structures ◽  
Relative Depth ◽  
Strengthening Effect ◽  
Back Side ◽  
Front Side ◽  
Finite Element Software

Defects like surface crack often appear in steel structures. To ensure the structural integrity and security, the new material such as fiber reinforced polymer (FRP) was adopted for strengthening and repairing. In this paper, three dimensional semi-elliptic surface crack in steel tension specimen strengthened with carbon fiber laminate (CFL) was studied, and numerical analysis was undertaken by Abaqus finite element software to study the stress intensity factor (SIF, KI) of the surface crack for CFL reinforcement effect. The results showed that, strengthening effect of CFL in front side was better than the back side of the steel plate; Crack shape ratio, a/c, had greater influence on strengthening effect in front side compared with little effect in the back side; The changes of crack relative depth, a/B, affected strengthening effect.

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