Theoretical and experimental investigations of localized CO2 laser-fused silica interactions and thermo-mechanical properties of mitigated sites

ABSTRACTThe mechanical properties of silica and titania-doped silica glasses, in bulk and fiber forms, are presented. These include the elastic properties (E and ν), strength distribution (in tension and bending), fatigue behavior (dynamic and static loading) and fracture toughness. Following a brief review of above properties for fused silica and ULE™ glasses (Coming Codes 7940 and 7971), used primarily for space applications, the mechanical properties data for silica and titania-doped silica-clad optical fibers are presented. The enhancement of mechanical performance of titania-doped silica clad fiber is also discussed.The effect of titania doping on fundamental properties like stress-free activation energy, crack tip pH, and deformation mode of Si-O-Si bond is discussed. In addition, the crack velocity data obtained from DCDC specimens of homogeneous silica and titania-doped silica glasses are compared in an attempt to understand the role titania plays in improving the fatigue resistance of optical fibers.

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Investigation on the influence of the CO2 laser parameters on the defect healing process of fused silica

10.1117/12.2618826 ◽

2021 ◽

Author(s):

Zican YANG ◽

Jian Cheng ◽

Linjie Zhao ◽

Mingjun Chen ◽

Jinghe Wang ◽

...

Keyword(s):

Co2 Laser ◽

Healing Process ◽

Fused Silica ◽

Laser Parameters ◽

Defect Healing

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Influence of Gradual Damage on the Structural Dynamic Behaviour of Composite Rotors: Experimental Investigations

Materials ◽

10.3390/ma11122421 ◽

2018 ◽

Vol 11 (12) ◽

pp. 2421 ◽

Cited By ~ 7

Author(s):

Angelos Filippatos ◽

Maik Gude

Keyword(s):

Mechanical Properties ◽

Composite Structures ◽

Dynamic Behaviour ◽

Experimental Investigations ◽

Catastrophic Failure ◽

Structural Dynamic ◽

Delamination Growth ◽

Reinforced Composite ◽

Out Of Plane ◽

Effective Mechanical Properties

Fibre-reinforced composite structures subjected to complex loads exhibit gradual damage behaviour with the degradation of the effective mechanical properties and changes in their structural dynamic behaviour. Damage manifests itself as a spatial increase in inter-fibre failure and delamination growth, resulting in local changes in stiffness. These changes affect not only the residual strength but, more importantly, the structural dynamic behaviour. In the case of composite rotors, this can lead to catastrophic failure if an eigenfrequency coincides with the rotational speed. The description and analysis of the gradual damage behaviour of composite rotors, therefore, provide the fundamentals for a better understanding of unpredicted structural phenomena. The gradual damage behaviour of the example composite rotors and the resulting damage-dependent dynamic behaviour were experimentally investigated under propagating damage caused by a combination of out-of-plane and in-plane loads. A novel observation is the finding that a monotonic increase in damage results in a non-monotonic frequency shift of a significant number of eigenfrequencies.

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Mechanical performance of polyester pin-reinforced foam filled honeycomb sandwich panels

Science and Engineering of Composite Materials ◽

10.1515/secm-2017-0039 ◽

2018 ◽

Vol 25 (4) ◽

pp. 797-805 ◽

Cited By ~ 4

Author(s):

R.S. Jayaram ◽

V.A. Nagarajan ◽

K.P. Vinod Kumar

Keyword(s):

Mechanical Properties ◽

Mechanical Performance ◽

Flexural Rigidity ◽

Sandwich Panels ◽

Interfacial Strength ◽

Structural Performance ◽

Experimental Investigations ◽

Honeycomb Sandwich ◽

Foam Filled ◽

Pin Reinforcement

Abstract Honeycomb sandwich panels entice continuously enhanced attention due to its excellent mechanical properties and multi-functional applications. However, the principal problem of sandwich panels is failure by face/core debond. Novel lightweight sandwich panels with hybrid core made of honeycomb, foam and through-thickness pin was developed. Reinforcing polyester pins between faces and core is an effectual way to strengthen the core and enhance the interfacial strength between the face/core to improve the structural performance of sandwich panels. To provide feasibility for pin reinforcement, honeycomb core was pre-filled with foam. Mechanical properties enhancement due to polyester pinning were investigated experimentally under flatwise compression, edgewise compression and flexural test. The experimental investigations were carried out for both “foam filled honeycomb sandwich panels” (FHS) and “polyester pin-reinforced foam filled honeycomb sandwich panels” (PFHS). The results show that polyester pin reinforcement in foam filled honeycomb sandwich panel enhanced the flatwise, edgewise compression and flexural properties considerably. Moreover, increasing the pin diameter has a larger effect on the flexural rigidity of PFHS panels. PFHS panels have inconsequential increase in weight but appreciably improved their structural performance.

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