scholarly journals Determining the Stages of Deformation and Destruction of Composite Materials in a Static Tensile Test by Acoustic Emission

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 313
Author(s):  
Katarzyna Panasiuk ◽  
Krzysztof Dudzik
Keyword(s):  
Acoustic Emission ◽  
Composite Materials ◽  
Construction Material ◽  
Construction Materials ◽  
Mechanical Tests ◽  
Test Methods ◽  
Permissible Stress ◽  
Fibre Breakage ◽  
Matrix Cracks ◽  
Starting Point

Composite materials are used in many industries. They are construction materials that are being used more and more often, which makes it necessary to accurately identify the process of their destruction. Recent decades have resulted in an intensive increase in diagnostic tests of structures and mechanical elements. Non-destructive testing (NDT) represents a group of test methods (surface and volumetric) that provide information about the properties of the tested element without changing its structure. The method of acoustic emission (AE) is also being used more frequently. Thanks to the ability to detect and locate signal sources, as well as to perform tests during operation, it is a method that is increasingly used in industry. In this article, the acoustic emission was used to analyze the changes occurring in composite materials. Obtained parameters helped to determine the signals originating from fibre delamination, fibre cracking, etc., as well as the starting point of these changes and the stress values at which these changes occurred. The analysis of acoustic emission signals recorded during the tests helped to determine the values of amplitudes characteristic for the destruction mechanisms of considered composite materials. Signals with an amplitude in the range of 30–41 dB may indicate elastic–plastic deformation of the matrix. Signals with an amplitude in the range of 42–50 dB indicate matrix cracks with the accompanying phenomenon of fibre delamination. Signals with amplitudes greater than 50 dB indicate fibre breakage. Based on the test results, the permissible stress was determined; when exceeded, the mechanisms of damage to the structure of composite materials accumulate. This stress limit for the tested material is 70 MPa. The use of the acoustic emission method in mechanical tests may contribute to a greater knowledge of composite materials used as a construction material, as well as determine the stresses allowable for a given structure.

Investigation of the Staging of Damage Accumulation in Polymer Composite Materials during Bending and Tensile Tests

2021 ◽  
Vol 887 ◽  
pp. 116-122
Author(s):  
A.A. Bryansky ◽  
O.V. Bashkov ◽  
Daria P. Malysheva ◽  
Denis B. Solovev
Keyword(s):  
Acoustic Emission ◽  
Composite Materials ◽  
Polymer Composite ◽  
Loading Rate ◽  
Tensile Tests ◽  
Mechanical Tests ◽  
Rate Effect ◽  
Polymer Composite Materials ◽  
Static Tension ◽  
Point Bend

The paper presents the results of the study of registered acoustic emission (AE) parameters during static deformation and damaging of polymer composite materials (PCM). Mechanical tests were done by a static tension and a static three-point bend, accompanied by an acoustic emission method. The assessment of the loading rate effect on defects formation processes was done by additional static tension test at rate equal half of recommended by the standard and static three-point bend test at rate ten times lower than that calculated by the standard. Clustering by frequency components of the recorded AE signals with a self-organizing Kohonen map was performed. The characteristics of the types of PCM structure damage by the centroids of the obtained clusters are given. Based on the clusters accumulation during mechanical tests, the stages of damage formation for static tension and static three-point bend, the loading rate effect on the process of damage formation are described.

MORPHOLOGICAL, MECHANICAL, THERMAL AND TRIBOLOGICAL PROPERTIES OF ENVIRONMENTALLY FRIENDLY CONSTRUCTION MATERIALS: RECYCLED LDPE COMPOSITES FILLED BY BLAST FURNACE DUST

2020 ◽  
Vol 15 (3) ◽  
pp. 159-175
Author(s):  
Merve Tuna Kayili ◽  
Gülser Çelebi ◽  
Abdulmecit Guldas
Keyword(s):  
Thermal Conductivity ◽  
Wear Resistance ◽  
Composite Material ◽  
Blast Furnace ◽  
Composite Materials ◽  
Steel Industry ◽  
Construction Materials ◽  
Mechanical Tests ◽  
Blast Furnace Dust ◽  
Ldpe Composites

ABSTRACT This study focused on developing a sustainable composite material using metallic wastes of the iron-steel industry and plastic wastes of the plastic industry in order to reduce resultant waste from the production processes of various industrial products and to sustain waste management of these industries. In this study, different amounts of blast furnace dust (BFD), which is the major iron-steel industry waste and is used as filler for recycled low-density polyethylene (LDPE), was mixed with LDPE to produce the composite material. The morphology, mechanical, vicat softening temperature thermal conductivity, hardness and wear resistance properties of BFD filled LDPE composites were assessed. The increasing of BFD in recycled LDPE improved the heat resistance, increased thermal conductivity and wear resistance of composite materials. In addition, it was found that the composite materials had sufficient mechanical properties, when mechanical tests were evaluated. These results showed that the produced composite material could be used in buildings as a floor coating material and thereby saving raw materials and resources, as well as potentially reducing environmental problems.

scholarly journals The Effectiveness of Sustainable Construction Materials by Using U-Shaped Composite Spacer Block (UCop)​

2019 ◽  
Vol 3 (1) ◽  
pp. 7-10
Author(s):  
Mohamed Saim ◽  
Keyword(s):  
Construction Material ◽  
Market Price ◽  
Construction Materials ◽  
Mechanical Tests ◽  
Sustainable Construction ◽  
Particle Board ◽  
Construction Costs ◽  
Minimum Requirement ◽  
Minimum Standards ◽  
New Construction

Nowadays in construction development, the needs of construction materials that have a unique reinforced concrete design with good quality, reasonable market price, and easy installation techniques has been prioritized. Therefore, this study aimed to produce an alternative new construction material that can fulfill the requirements. The U-shaped composite spacer block (UCop) through the production of Cement Bonded Particle Board (CBPB) as a specimen block was produced from the wood waste of carpentry work combined with Shorea spp. (Seraya red and white) particle size approximately 0.4mm - 2.00 mm. Then it was mixed together with Portland cement by using a ratio 1:2.5. The mixture was then added with Ammonia Chloride (Al2SO4) and Calcium Chloride (CaCl2) act as additives for this product. The physical and mechanical tests were conducted in this study. The results were showed that the thickness expansion was achieved an average of 1.79 %, which was passed the minimum requirement of MS934:1986 standards. However, the flexural strength did not meet the minimum standards. The poor mixing technique was attributed to the results. However, UCop still could contribute as an alternative solution in ease the concrete pouring process using a special binder, giving the spacer block any resistance to formwork of columns or beams is filled with concrete. The high-impact innovations of this product in construction such as it can help the process to be more efficient and to reduce construction costs, next indirectly preserve the nature.

scholarly journals Evaluation of Mechanical, Physical, and Morphological Properties of Epoxy Composites Reinforced with Different Date Palm Fillers

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2145 ◽  
Author(s):  
Basheer A. Alshammari ◽  
Naheed Saba ◽  
Majed D. Alotaibi ◽  
Mohammed F. Alotibi ◽  
Mohammad Jawaid ◽  
...  
Keyword(s):  
Composite Materials ◽  
Date Palm ◽  
Mechanical Tests ◽  
Epoxy Composites ◽  
Morphological Properties ◽  
Mechanical Resistance ◽  
Palm Tree ◽  
Palm Fruit ◽  
Pull Out ◽  
Matrix Cracks

The present study deals with the fabrication of epoxy composites reinforced with 50 wt% of date palm leaf sheath (G), palm tree trunk (L), fruit bunch stalk (AA), and leaf stalk (A) as filler by the hand lay-up technique. The developed composites were characterized and compared in terms of mechanical, physical and morphological properties. Mechanical tests revealed that the addition of AA improves tensile (20.60–40.12 MPa), impact strength (45.71–99.45 J/m), flexural strength (32.11–110.16 MPa) and density (1.13–1.90 g/cm3). The water absorption and thickness swelling values observed in this study were higher for AA/epoxy composite, revealing its higher cellulosic content, compared to the other composite materials. The examination of fiber pull-out, matrix cracks, and fiber dislocations in the microstructure and fractured surface morphology of the developed materials confirmed the trends for mechanical properties. Overall, from results analysis it can be concluded that reinforcing epoxy matrix with AA filler effectively improves the properties of the developed composite materials. Thus, date palm fruit bunch stalk filler might be considered as a sustainable and green promising reinforcing material similarly to other natural fibers and can be used for diverse commercial, structural, and nonstructural applications requiring high mechanical resistance.

The Mechanical Properties of Organic Modified Epoxy Resin

2020 ◽  
Vol 43 (3) ◽  
pp. 10-14
Author(s):  
Georgel MIHU ◽  
Claudia Veronica UNGUREANU ◽  
Vasile BRIA ◽  
Marina BUNEA ◽  
Rodica CHIHAI PEȚU ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Epoxy Resin ◽  
Epoxy Matrix ◽  
Epoxy Resins ◽  
Mechanical Tests ◽  
Organic Modification ◽  
Three Point Bending ◽  
Modified Epoxy

Epoxy resins have been presenting a lot of scientific and technical interests and organic modified epoxy resins have recently receiving a great deal of attention. For obtaining the composite materials with good mechanical proprieties, a large variety of organic modification agents were used. For this study gluten and gelatin had been used as modifying agents thinking that their dispersion inside the polymer could increase the polymer biocompatibility. Equal amounts of the proteins were milled together and the obtained compound was used to form 1 to 5% weight ratios organic agents modified epoxy materials. To highlight the effect of these proteins in epoxy matrix mechanical tests as three-point bending and compression were performed.

Bamboo Waste-based Bio-composite Substance: An application for Low-cost Construction Materials

2020 ◽  
Vol 4 (1) ◽  
pp. 41-48
Author(s):  
Teodoro Astorga Amatosa ◽  
Michael E. Loretero
Keyword(s):  
Composite Materials ◽  
Sea Water ◽  
Raw Materials ◽  
Low Cost ◽  
Construction Materials ◽  
Single Layer ◽  
High Strength ◽  
Green Technology ◽  
Experimental Medium ◽  
Natural Treatment

Bamboo is a lightweight and high-strength raw materials that encouraged researchers to investigate and explore, especially in the field of biocomposite and declared as one of the green-technology on the environment as fully accountable as eco-products. This research was to assess the technical feasibility of making single-layer experimental Medium-Density Particleboard panels from the bamboo waste of a three-year-old (Dendrocalamus asper). Waste materials were performed to produce composite materials using epoxy resin (C21H25C105) from a natural treatment by soaking with an average of pH 7.6 level of sea-water. Three different types of MDP produced, i.e., bamboo waste strip MDP (SMDP), bamboo waste chips MDP (CMDP) and bamboo waste mixed strip-chips MDP (MMDP) by following the same process. The experimental panels tested for their physical-mechanical properties according to the procedures defined by ASTM D1037-12. Conclusively, even the present study shows properties of MDP with higher and comparable to other composite materials; further research must be given better attention as potential substitute to be used as hardwood materials, especially in the production, design, and construction usage.

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