Additive metal solutions to aircraft skin corrosion

2020 ◽  
Vol 124 (1276) ◽  
pp. 872-887
Author(s):  
N. Matthews ◽  
R. Jones ◽  
D. Peng ◽  
N. Phan ◽  
T. Nguyen
Keyword(s):  
Experimental Investigation ◽  
Carrying Capacity ◽  
Particle Deposition ◽  
Corrosion Damage ◽  
Experimental Results ◽  
Load Carrying Capacity ◽  
Transport Aircraft ◽  
Load Carrying ◽  
Aircraft Skin ◽  
The Common

ABSTRACTThis paper focuses on the problem of skin corrosion on the upper wing surfaces of rib-stiffened aircraft. For maritime and military transport aircraft this often results in multiple co-located repairs. The common approach to corrosion damage in operational aircraft is to blend out the corrosion and rivet a mechanical doubler over the region. In particular this paper describes the results of a combined numerical and experimental investigation into the ability of the additive metal technology, Supersonic Particle Deposition (SPD), to restore the load-carrying capacity of rib-stiffened wing planks with simulated skin corrosion. The experimental results reveal that unrepaired skin corrosion can result in failure by yielding. The experimental results also reveal that SPD repairs to skin corrosion can restore the stress field in the structure, and can ensure that the load-carrying capability of the repaired structure is above proof load.

Analytical study on repair method for steel I-girder bridges with corrosion damage considering its structural system behavior

2021 ◽  
Author(s):  
Ryoga Oura ◽  
Takashi Yamaguchi ◽  
Kentaro Arimura
Keyword(s):  
Carrying Capacity ◽  
Corrosion Damage ◽  
Load Carrying Capacity ◽  
Structural Members ◽  
Structural System ◽  
System Behavior ◽  
Girder Bridges ◽  
Load Carrying ◽  
Girder Bridge ◽  
The Individual

<p>Bridges are composed by many structural members which interact with each other to resist against various load combinations. Considering damage repair of one of its structural members, the relationship between the recovery of the individual load-carrying capacity due to the repair of a single member and the improvement of the load-carrying capacity of the structural system is not clear. In the present study, a full-scale FE analysis has been conducted for a steel I-girder bridge system with corrosion damages which have been repaired. The analysis considered, the structural system behavior, varying the repaired areas and the type of patch members. From the analytical results, it was found that, compared to the method in which the damaged portion is completely repaired, the amount of repair can be reduced by taking into account the structural system behavior and partially repair both the damaged and the adjacent intact girders.</p>

EXPERIMENTAL INVESTIGATION OF CFRP STRENGTHENED I-SHAPED COLD FORMED STEEL BEAMS

2017 ◽  
Vol 79 (5) ◽  
Author(s):  
Nahushananda Chakravarthy ◽  
Sivakumar Naganathan ◽  
Jonathan Tan Hsien Aun ◽  
Sreedhar Kalavagunta ◽  
Kamal Nasharuddin Mustapha ◽  
...  
Keyword(s):  
Carrying Capacity ◽  
Experimental Results ◽  
Steel Beams ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Length Width ◽  
Cold Formed Steel ◽  
Formed Channel ◽  
Hot Rolled ◽  
Hot Rolled Steel

Cold formed steel differ from hot rolled steel by its lesser thickness and weight. The cold formed steel applicable in roof purlin, pipe racks and wall panels etc. Due its lesser wall thickness the cold formed steel member subjected to buckling. The enhancement of load carrying capacity of the cold formed steel member can be achieved by external strengthening of CFRP. In this study cold formed channel members connected back to back to form I shaped cross section using screws. These built up beam members were 300mm, 400mm and 500mm in length with 100mm screw spacing and edge distance of 50mm were chosen for testing. CFRP fabric cut according to length, width of built up beams and wrapped outer surface of beam using epoxy resin. Experiments were carried out in two sets firstly plain built up beams and secondly CFRP wrapped beams. The test results shows that increased load carrying capacity and reduction in deflection due to CFRP strengthening. Experimental results were compared with AISI standards which are in good agreement. Experimental results shows that CFRP strengthening is economic and reliable.

A study into the ability of SPD to restore the buckling strength and modes of rib stiffened panels with simulated stress corrosion cracks

2017 ◽  
Vol 8 (1) ◽  
pp. 63-78 ◽  
Author(s):  
Rhys Jones ◽  
Neil Matthews ◽  
Daren Peng ◽  
Nicholas Orchowski
Keyword(s):  
Experimental Study ◽  
Stress Corrosion ◽  
Carrying Capacity ◽  
Particle Deposition ◽  
Load Carrying Capacity ◽  
Load Path ◽  
Premature Failure ◽  
Content Type ◽  
Buckling Strength ◽  
Load Carrying

Purpose The purpose of this paper is to describe the results of a combined numerical and experimental study into the ability of supersonic particle deposition (SPD) to restore the load carrying capacity of rib stiffened wing planks with simulated stress corrosion cracking (SCC). Design/methodology/approach In this context the experimental results reveal that SCC can result in a dramatic reduction in the load carrying capacity of the structure and catastrophic failure via cracking that tears the length of the structure through buckling. A combined numerical and experimental study then reveals how this reduction, in the load carrying capacity can be overcome by using SPD. Findings This paper is the first to show that SPD can be used to restore the load carrying capacity of rib stiffened structures with SCC. It also shows that SPD repairs can be designed to have only a minimal effect on the local stiffness and hence on the load path. However, care should be taken to ensure that the design is such that premature failure of the SPD does not occur. Originality/value This is the first paper to show that a thin layer of SPD deposited 7,075 aluminium alloy powder on either side of the SCC-simulated stiffener has the potential to restore the load carrying capability of a rib stiffened structure. As such it represents an important first step into establishing the potential for SPD to restore the buckling strength of rib stiffened wing panels containing SCC.

Investigation on the Post-Ultimate Strength Behaviour of Sandwich Plate

2014 ◽  
Author(s):  
Wei Wang ◽  
Weijun Xu ◽  
Xiongliang Yao ◽  
Nana Yang
Keyword(s):  
Ultimate Strength ◽  
Carrying Capacity ◽  
Failure Modes ◽  
Sandwich Plate ◽  
Experimental Results ◽  
Sandwich Plates ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Strength Behavior ◽  
Simulation Results

This paper focuses on the post-ultimate strength behavior of sandwich plates. With widely application of the laminate on the ship and offshore structures, the post-ultimate strength behavior is becoming more important for safety evaluation of structures. Since the post-ultimate strength behavior can reflect the collapse extent of sandwich plate when subjected to extreme loads. A sandwich plate was modeled by FEM, its load-displacement relationship was obtained and its collapse characteristics were analyzed. The load-displacement relationship indicates its post-ultimate strength behavior, which is shown as that the load carrying capacity has a rapidly reduction when the ultimate strength is exceeded, and that the failure modes of the sandwich plate are determined by the parameter of individual layer. The simulation results were validated against experimental results. Conclusions are drawn: the displacement of sandwich plate under axial compression increased slowly before reaching the ultimate strength, once the ultimate strength was exceeded, the loads exerted on the structures sharply decreased with slowly increased displacement until the plate cracked. The simulation results have a good agreement with the experimental results. The mainly failure modes of sandwich plates can be interpreted as delamination between skin & core and core compression fracture, which are typical failure modes in engineering. The stiffness of sandwich structures decreased due to the interlaminar cracking or skin fracture, further the load carrying capacity decreased, which is of significance for guiding the design of sandwich structures.

Force Transfer Mechanism in Embedded Steel Column Bases

2006 ◽  
Vol 326-328 ◽  
pp. 1805-1810 ◽  
Author(s):  
Young Ho Kim ◽  
Seung Sik Lee ◽  
Jae Ho Jung ◽  
Soon Jong Yoon
Keyword(s):  
Shear Strength ◽  
Bond Strength ◽  
Carrying Capacity ◽  
Experimental Results ◽  
Load Carrying Capacity ◽  
Force Transfer ◽  
Load Carrying ◽  
Steel Column ◽  
Force Transfer Mechanism ◽  
Column Base

This paper presents the results of an investigation on the force transfer mechanism in an embedded column base of a composite structure. In the experimental program, eighteen push-out specimens were tested. The factors influencing the mechanism of force transfer were the amount of confining reinforcement, compressive strength of concrete, and diameter of stud connectors. The results of experiment indicated that force transfer could be characterized into two stages, and the factors governing each stage were identified. The first stage was governed by the bond strength between the steel column base and the concrete. The second stage begun after chemical debonding and was governed by the shear strength of stud connectors as well as the frictional strength between the steel and the concrete. Based on the experimental results, the equations to estimate the bond strength, the friction strength, and the shear strength of stud connectors were proposed. The load carrying capacity of an embedded steel column base could be predicted by taking the sum of the shear strength of stud connectors and the friction strength. The predicted load carrying capacity was found to agree well with the experimental results over various range of concrete stress.

Research on Behavior of Ultra-High Toughness Cementitious Composites Reinforced Frame Joints

2011 ◽  
Vol 71-78 ◽  
pp. 794-798
Author(s):  
Jun Su ◽  
Shi Lang Xu ◽  
Dong Tao Xia
Keyword(s):  
Energy Dissipation ◽  
Carrying Capacity ◽  
Experimental Analysis ◽  
Experimental Results ◽  
Hysteretic Behavior ◽  
Cementitious Composites ◽  
Load Carrying Capacity ◽  
High Toughness ◽  
Load Carrying ◽  
Axial Compressive Ratio

In this article, through the seismic experimental analysis for six frame joints of ultra-high toughness cementitious composites, the load-carrying capacity, hysteretic behavior, energy dissipation and ductility of new joints are studied under different axial compressive ratio and the stirrups space. The experimental results show that the UHTCC joints have higher anti-cracking capacity and shear ductility. The UHTCC can reduce or even eliminate the amount of shear stirrups of the joint core. According to the analysis for the experiments, a theoretical calculating formula of shearing capacity is presented, whose calculating results agree well with the experimental results.

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