Mechanisms of solid particle erosion damage in the repair of damaged composite structures

The effect of solid particle erosion on the strength properties of E-glass/epoxy composite was investigated. Solid particle erosion with SiC particles 400 μm to 500 μm in diameter was simulated on 12 ply [45°/−45°/0°/45°/−45°/0°]s E-glass/epoxy composites with constant particle velocity of 42.5 m/s at impact angles of 90°, 60°, and 30° for 30, 60, 90 and 120 seconds. Damaged and undamaged specimens were subjected to tensile tests while monitoring their acoustic emission (AE) activity. An erosion damage parameter was defined as a function of the particle impact angle and erosion duration to determine the residual tensile strength of the composite. Scanning electron microscope (SEM) images of the erosion damaged specimens revealed the same damage mechanism occurred at different impact angles. The distribution of AE events by event duration, ring down counts and energy distribution were used to characterize the different damage mechanisms that occurred during tensile loading of damaged and undamaged specimens. The results showed AE activity could be used to distinguish between different damage mechanisms within the composite, such as fiber/matrix debonding, delamination and fiber fracture. The Weibull probability distribution model and the AE stress delay parameter model were developed to relate the AE activity to the erosion damage and residual strength. The results showed both the Weibull probability model and the stress delay model could be used to predict residual strength of the composites.

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Solid Particle Erosion Characteristics of 2.25Cr–1Mo Steel Aged at 750 °C

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2020.17592 ◽

2020 ◽

Vol 20 (7) ◽

pp. 4513-4516

Author(s):

Kwang-Hu Jung ◽

Seong-Jong Kim

Keyword(s):

Stainless Steel ◽

Flow Velocity ◽

Aging Time ◽

Solid Particle ◽

Vickers Hardness ◽

Surface Hardness ◽

Solid Particle Erosion ◽

Particle Erosion ◽

Erosion Damage ◽

Damage Type

This study evaluated the solid particle erosion characteristics of 2.25Cr–1Mo steel with aging time. Aging was performed at 750 °C until 100 h. Specimens aged at each time were characterized by microstructure analysis and Micro-Vickers hardness. An erosion experiment was conducted using 100~200 μm of stainless steel shot at a flow velocity of 20 m/s for 4 h. A consequently, a microstructure degradation phenomenon in which Cr-rich carbide was coarsened occurred, and the surface hardness decreased by 45%. With a decrease in the hardness, the solid particle erosion damage increased and the erosion damage type changed.

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Assessment of Remaining Life of a Control Stage Blade With Solid Particle Erosion Damage

Volume 3A: General ◽

10.1115/93-gt-241 ◽

1993 ◽

Author(s):

Tony C.-T. Lam ◽

Thomas H. McCloskey ◽

Robert P. Dewey ◽

Paul Wawrzynek

Keyword(s):

Solid Particle ◽

Structural Integrity ◽

Service Failure ◽

Three Dimensional ◽

Solid Particle Erosion ◽

Remaining Life ◽

Particle Erosion ◽

Erosion Damage ◽

Mechanics Model ◽

Control Stage

Unscheduled replacement of HP control stage blades due to solid particle erosion can be avoided if the structural integrity of the eroded blade has not been compromised, and the risk of an in-service failure is shown to be minimal. An analytical approach is presented which was used to evaluate whether blades with SPE damage could remain in service until the next convenient outage, in order to provide the plant engineers with specifications to assist them in determining the need for replacement based on further observed erosion damage. A three-dimensional fracture mechanics model was applied to study the propagation of cracks caused by erosion, and to assess when rupture was likely to occur. The results of the study are presented as a model for plant operators to use in scheduling the repair or replacement of HP blades.

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Preparation and Solid Particle Erosion Behaviors of Plasma-Sprayed and Laser-Remelted ZrO2-7wt.%Y2O3 Thermal Barrier Coatings

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.159.191 ◽

2012 ◽

Vol 159 ◽

pp. 191-197 ◽

Cited By ~ 2

Author(s):

Dong Sheng Wang ◽

Zong Jun Tian ◽

Bin Yang ◽

Li Da Shen

Keyword(s):

Solid Particle ◽

Thermal Barrier Coatings ◽

Thermal Barrier ◽

Solid Particle Erosion ◽

Laser Remelting ◽

Particle Erosion ◽

Barrier Coatings ◽

Erosion Damage ◽

Sprayed Coating ◽

Plasma Sprayed

In this study, ZrO2-7wt.%Y2O3 thermal barrier coatings (TBCs) were prepared on TiAl base intermetallic alloy substrates by plasma spraying process. After that, the plasma-sprayed TBCs were laser remelted using a CO2 laser. Influences of laser remelting on the microstructure and solid particle erosion characterization of the coatings were researched. Meanwhile, the erosion damage modes of the two types of TBCs were discussed. The results show that the as-sprayed TBC has a typical lamellar stacking characteristic. The lamellar defect of the plasma-sprayed coating is erased, and the compactness of the coating is improved significantly after laser remelting. The laser-remelted coating consists of column-like crystals along the direction of the heat current. The laser-remelted coating had better erosion resistance than the as-sprayed coating. Owing to the limited bonding at the interfaces between lamellar, the spalling of the sprayed splats from the lamellar interface is mainly attributed to the erosion failure of the as-sprayed coating. In addition, crushing of brittle ceramic coating is also responsible for the erosion damage of the plasma-sprayed TBC. In contrast, cracking occurs within region near the surface of the laser-remelted layer and that erosion occurs mainly by removal of these small blocks. Moreover, the laser-remelted has evident mciro-cutting marks and shows some ductile erosion characteristic.

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The Effect of Solid Particle Erosion on the Mechanical Properties and Fatigue Life of Fiber-Reinforced Composites

Materials, Nondestructive Evaluation, and Pressure Vessels and Piping ◽

10.1115/imece2006-13491 ◽

2006 ◽

Author(s):

N. H. Yang ◽

H. Nayeb-Hashemi

Keyword(s):

Tensile Strength ◽

Fatigue Life ◽

Solid Particle ◽

Impact Angle ◽

Fatigue Properties ◽

Particle Impact ◽

Solid Particle Erosion ◽

Particle Erosion ◽

Erosion Damage ◽

Impact Angles

The effect of solid particle erosion on the strength and fatigue properties of E-glass/epoxy composite was investigated. Solid particle erosion with SiC particles of 400 μm to 500 μm in diameter was simulated on 12 ply [45°/-45°/0°/45°/-45°/0°]s E-glass/epoxy composites with a constant particle velocity of 42.5 m/s and solid particle to air volume ratio of 6 kg/m3 at impact angles of 90°, 60°, and 30° for 30, 60, 90 and 120 seconds. Damaged and undamaged specimens were subjected to tensile tests while monitoring their acoustic emission (AE) activity. An erosion damage parameter was defined as a function of the particle impact angle and erosion duration to determine the residual tensile strength of the composite. Scanning electron microscope (SEM) images of the erosion damaged specimens revealed the same damage mechanism occurred at different impact angles. The AE stress delay parameter was used to predict the residual tensile strength of erosion damaged composites. Tension-tension fatigue tests were performed on virgin specimens and specimens exposed to erosion damage of 60 seconds and 90 seconds at 90° particle impact angle to observe the effects of erosion damage on the fatigue life. A modified Basquin's equation was defined to predict the fatigue life of the erosion damaged specimens.

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