Electromechanical Analysis of a Piezoelectric Instrumented Composite Bonded Repair Patch

2020 ◽  
pp. 771-778
Author(s):  
T. S. Koko ◽  
N. Mrad ◽  
B. K. Gallant ◽  
T. Dunbar ◽  
P. Masson
Keyword(s):  
Repair Patch ◽  
Bonded Repair

scholarly journals Health monitoring of a bonded repair patch using small-diameter FBG sensors

2003 ◽  
Vol 2003.9 (0) ◽  
pp. 181-182
Author(s):  
T. Yamamoto ◽  
S. Takeda ◽  
Y. Okabe ◽  
N. Takeda
Keyword(s):  
Health Monitoring ◽  
Small Diameter ◽  
Repair Patch ◽  
Bonded Repair ◽  
Fbg Sensors

Structural Health Monitoring of Bonded Patch Repaired Composite

2016 ◽  
Vol 713 ◽  
pp. 135-138 ◽  
Author(s):  
Florian Lambinet ◽  
Zahra Sharif Khodaei ◽  
M.H. Ferri Aliabadi
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Composite Structures ◽  
Fatigue Testing ◽  
Impact Damage ◽  
Electromechanical Impedance ◽  
Structural Health ◽  
Repair Patch ◽  
Bonded Repair ◽  
First Case

Bonded repair of composite structures still remains a crucial concern for the airworthiness authorities because of the uncertainty about the repair quality. This works, investigates the applicability of Structural Health Monitoring (SHM) techniques for monitoring of bonded repair. Active sensing method has been applied to two case studies: a sensorised panel impacted to cause barely visible impact damage (BVID) and repaired afterwards, the tensile and fatigue testing of a composite strap repair. In the first case, the previous sensors have been used to detect an artificially introduced damage. In the second case the failure of the adhesive during the tensile testing is used as basis of the load levels in the tensile-tensile fatigue test. In both cases PZT transducers have been used to monitor the bonded patch. An electromechanical impedance (EMI) and Lamb wave analysis have been carried out to check the overall integrity of the repair patch between. In both cases the state of the repaired composite was monitored successfully and reported.

The effects of size and stacking sequence of composite laminated patch on bonded repair for cracked hole

1996 ◽  
Vol 3 (6) ◽  
pp. 355-367 ◽  
Author(s):  
Ching-Hwei Chue ◽  
Wen-Ching Chou ◽  
Thomas Jin-Chee Liu
Keyword(s):  
Stacking Sequence ◽  
Bonded Repair ◽  
Cracked Hole

scholarly journals Repair of abasic sites by mammalian cell extracts

1994 ◽  
Vol 304 (3) ◽  
pp. 699-705 ◽  
Author(s):  
G Frosina ◽  
P Fortini ◽  
O Rossi ◽  
F Carrozzino ◽  
A Abbondandolo ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Excision Repair ◽  
Chinese Hamster ◽  
Pyrimidine Dimer ◽  
Repair Synthesis ◽  
Repair Patch ◽  
Cell Extracts ◽  
Pyrimidine Dimers ◽  
Ap Sites ◽  
Ap Site

Hamster cell extracts that perform repair synthesis on covalently closed circular DNA containing pyrimidine dimers, were used to study the repair of apurinic/apyrimidinic (AP) sites and methoxyamine (MX)-modified AP sites. Plasmid molecules were heat-treated at pH 5 and incubated with MX when required. The amount of damage introduced ranged from 0.2 to 0.9 AP sites/kb. Extracts were prepared from the Chinese hamster ovary CHO-9 cell line and from its derivative, 43-3B clone which is mutated in the nucleotide excision repair (NER) ERCC1 gene. AP and MX-AP sites stimulated repair synthesis by CHO-9 cell extracts. The level of synthesis correlated with the number of lesions and was of similar magnitude to the repair stimulated by 4.3 u.v. photoproducts/kb. Repair of AP and MX-AP sites was faster than the repair of u.v. damage and was independent of ERCC1 gene product. The high level of repair replication was due to a very efficient and rapid incision of plasmids carrying AP or MX-AP sites, performed by abundant AP endonucleases present in the extract. The calculated average repair patch sizes were: 7 nucleotides per AP site; 10 nucleotides per MX-AP site; 28 nucleotides per (6-4) u.v. photoproduct or cyclobutane pyrimidine dimer. The data indicate that AP and MX-AP sites are very efficiently repaired by base-excision repair in mammalian cells and suggest that MX-AP sites may also be processed via alternative repair mechanisms.

scholarly journals Triblock Copolymer Toughening of a Carbon Fibre-Reinforced Epoxy Composite for Bonded Repair

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 888 ◽  
Author(s):  
Andrew Charles ◽  
Andrew Rider
Keyword(s):  
Fracture Toughness ◽  
Triblock Copolymer ◽  
Peel Strength ◽  
Positive Pressure ◽  
Resin System ◽  
Strength Performance ◽  
Performance Improvements ◽  
Bonded Repair ◽  
Epoxy Resin System ◽  
Bonded Composite

Epoxy resins are the most widely used systems for structural composite applications; however, they lack fracture toughness, impact strength and peel strength due to high cross-linking densities. Use of conventional toughening agents to combat this can lead to reductions in mechanical, thermal and processability properties desirable for bonded composite applications. In this work, an asymmetric triblock copolymer of poly(styrene)–b–poly(butadiene)–b–poly(methylmethacrylate) was used to modify an epoxy resin system, with the materials processed using both vacuum bag and positive pressure curing techniques. Interlaminar fracture toughness testing showed improvements in initiation fracture toughness of up to 88%, accompanied by a 6 °C increase in glass transition temperature and manageable reductions in gel-time. Shear testing resulted in a 121% increase in ultimate shear strain with only an 8% reduction in shear strength. Performance improvements were attributed to nano-structuring within the toughened resin system, giving rise to matrix cavitation and dissipation of crack front strain energy upon loading.

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