Hygrothermal Ageing Influence on BVI-Damaged Carbon/Epoxy Coupons under Compression Load

Composite materials usage in several industrial fields is now widespread, and this leads to the necessity of overcoming issues that are still currently open. In the aeronautic industry, this is especially true for Barely Visible Impact Damage (BVID) and humidity uptake issues. BVID is the most insidious kind of impact damage, being rather common and not easily detectable. These, along with the ageing that a composite structure could face during its operative life, could be a cause of fatal failures. In this paper, the influence of water absorption on impacted specimens compressive residual strength was studied. Specimens were impacted using a modified Charpy pendulum. Two different locations were chosen for comparison: Near-Edge (NE) and Central (CI). Accelerated hygrothermal ageing was conducted on impacted and reference nonimpacted coupons, placing them in a water-filled jar at 70 °C. Compressive tests were performed in accordance with the Combined Loading Compression (CLC) test method. A Dynamic Mechanical Analysis (DMA) was performed as well. The results showed the influence of hygrothermal ageing, as expected. Nevertheless, the influence of impact location on compressive residual strength is not clearly noticeable in aged specimens, leading to the conclusion that hygrothermal ageing may have a greater effect on composite compressive strength than the analysed BVI damage.

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Numerical Investigation on the Ultimate Strength of Box Beams with Impact Damage

Journal of Marine Science and Application ◽

10.1007/s11804-020-00177-9 ◽

2020 ◽

Author(s):

Wei Xu ◽

C. Guedes Soares

Keyword(s):

Residual Stress ◽

Ultimate Strength ◽

Impact Damage ◽

Ship Hulls ◽

Four Point Bending ◽

Impact Location ◽

Box Beam ◽

Box Beams ◽

Fracture Damage ◽

The Impact

AbstractThe objective of this paper is to study the residual ultimate strength of box beams with impact-induced damage, as a model of what may occur in ship hulls. The bottom and side plates of ship hulls can suffer denting or fracture damage due to grounding, collision and other contacts during the ship’s service life and these impact-induced damages could result in considerable strength degradation. Box beams are firstly subjected to impact loading and then four-point bending loading is imposed on the damaged structures to assess the residual strength using ANSYS/LS_DYNA. The ultimate moment and collapse modes are discussed considering the effect of impact location. The impact-induced deformation is introduced in the four-point bending simulation, and the impact-induced stress is included or not to determine the effect of residual stress and distortion after impact. It is shown that impact location has significant influence on the residual ultimate bending moment of the damaged box beam providing that the impact energy is kept constant. The collapse modes also change when the impactor strikes on different locations. Damaged hard corner and inclined neutral axes might explain the reduction of ultimate strength and diverse collapse modes. The residual stress in the box beam after impact may increase or decrease the ultimate strength depending on impact location.

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Influence of shear test method and restraint condition on residual strength of granular materials

Powders and Grains 2001 ◽

10.1201/9781003077497-74 ◽

2020 ◽

pp. 301-304

Author(s):

Mitsuhiko Mukitani ◽

Norio Yagi ◽

Ryuichi Yatabe

Keyword(s):

Granular Materials ◽

Residual Strength ◽

Shear Test ◽

Test Method

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Fabricación de ladrillos con polvo-residuo de mármol en México

Revista de Arquitectura ◽

10.14718/revarq.2020.2554 ◽

2020 ◽

Author(s):

Cesar Ponce Palafox ◽

Julián Carrillo ◽

Areli López-Montelongo

Keyword(s):

Management Plan ◽

Experimental Program ◽

Compression Tests ◽

Seismic Demands ◽

Load Bearing ◽

Compression Load ◽

Palabras Clave ◽

Marble Powder ◽

The Individual ◽

Compressive Tests

Resumen La industria del mármol genera gran cantidad de desperdicio en polvo. Estos desechos carecen de un adecuado plan de manejo, además de resultar altamente contaminantes a la población que rodea el lugar de los depósitos de estos materiales. Para ofrecer una solución, en este artículo se presentan los resultados del desarrollo de un ladrillo a base del polvo de mármol. El programa experimental incluye 16 dosificaciones diferentes en las que se varía la cantidad de cemento, cal y arena, y se deja constante el polvo de mármol. El programa incluye el ensayo a compresión de 160 ladrillos, 3 ensayos a compresión en muretes, 3 pruebas de adherencia a compresión en muretes y 48 pruebas de absorción. Los resultados de compresión y adherencia demostraron que estos ladrillos podrían ser utilizados para la construcción de muros de carga en vivienda desarrolladas en zonas de amenaza sísmica baja. Palabras clave: Absorción; adherencia; compresión; muros de carga; vivienda Abstract The marble industry generates large amount of dust waste. These wastes do not have a proper management plan, as well as being highly contaminating the population surrounding the site of the deposits of these materials. To offer a solution, this article shows the results of the development of a brick-based marble powder to achieve sufficient compressive strength to construction masonry walls in low-rise housing. The experimental program includes 16 different dosages that varies the amount of cement, lime, and sand, and keeping constant the marble powder. The program includes the compressive tests for 160 bricks, compressive tests for 3 small walls, validated adherence under compression tests for 3 small walls, and absorption tests for 48 bricks. The results of the test showed that the compression strength of the individual bricks and wall is 4.0 MPa y 1.9 MPa, respectively, and the absorption of the bricks es 21 %. This results of absorption , compression and adhesion are a first indication of the feasibility of used these bricks for the construction of load-bearing walls in housing developed in areas of low seismic demands. Key Words: Absorption; adhesion; compression; load-bearing walls; housing

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Experimental and simulation investigation on BVID and CAI behaviors of CFRP laminates manufactured by RTM technology

Engineering Computations ◽

10.1108/ec-01-2020-0008 ◽

2020 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Fang Chen ◽

Weixing Yao ◽

Wen Jiang

Keyword(s):

Compressive Strength ◽

Impact Damage ◽

Projection Area ◽

Element Analysis ◽

Mechanical Fracture ◽

Content Type ◽

Explicit Finite Element ◽

Compression Load ◽

Cfrp Laminates ◽

The Impact

Purpose The purpose of this paper is to synthetically investigate the impact damage responses of carbon fiber reinforced polymer (CFRP) and its influence on the compression mechanical responses of CFRP laminates, including damage distribution, residual compressive strength and fracture morphology. Design/methodology/approach A progressive damage simulation model is developed to analyze the complicated damage responses of CFRP laminates that are manufactured by resin transfer method (RTM) technology. Based on the ABAQUS/explicit finite element analysis solver, a VUMAT code is proposed to descript the composite materials’ damage behaviors under both impact and compression load. Adopting this proposed model, the primary mechanical indicators of four groups’ 5284RTM/U3160 CFRP laminates with different stacking sequences are predicted. Moreover, impact and compression after impact tests are conducted to verify the accuracy of simulation results. Findings Both simulation and experimental results show that the impact damage with low visible detectability can significantly reduce composites’ compressive strength. For all four groups’ composite laminates, the residual strength ratio is around 35% or even lower. The kernel impact damage near the plates’ geometric center promotes the degradation process of local materials and finally leads to the early occurrence of mechanical fracture. In addition, the impact damage projection area is not sensitive to the parameters of stacking sequences, while the residual compression strength is proportional to the number of 0-degree layers within whole laminates. Originality/value This study helps to understand the effect of an impact event on CFRP laminates’ compressive bearing capacity and provides a numerical method in simulating the damage responses under both impact and compression load.

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A Preliminary Proposition for a Test Method to Measure (Impact) Damage Resistance

Journal of Reinforced Plastics and Composites ◽

10.1177/073168449301200508 ◽

1993 ◽

Vol 12 (5) ◽

pp. 584-601 ◽

Cited By ~ 57

Author(s):

Paul A. Lagace ◽

James E. Williamson ◽

P.H. Wilson Tsang ◽

Edward Wolf ◽

Stephen Thomas

Keyword(s):

Impact Damage ◽

Test Method ◽

Damage Resistance

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Impact damage assessment by using peridynamic theory

Open Engineering ◽

10.2478/s13531-012-0025-1 ◽

2012 ◽

Vol 2 (4) ◽

Cited By ~ 18

Author(s):

Erkan Oterkus ◽

Ibrahim Guven ◽

Erdogan Madenci

Keyword(s):

Residual Strength ◽

Damage Assessment ◽

Impact Damage ◽

Material Model ◽

Mixed Mode Fracture ◽

Simple Material ◽

Peridynamic Theory ◽

Load Paths ◽

Compression After Impact ◽

Building Components

AbstractThis study presents an application of peridynamic theory for predicting residual strength of impact damaged building components by considering a reinforced panel subjected to multiple load paths. The validity of the approach is established first by simulating a controlled experiment resulting in mixed-mode fracture of concrete. The agreement between the PD prediction and the experimentally observed behavior is remarkable especially considering the simple material model used for the concrete. Subsequently, the PD simulation concerns damage assessment and residual strength of a reinforced panel under compression after impact due to a rigid penetrator.

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