scholarly journals Adhesive compound of composite materials in conditions of accelerated climatic aging

Vestnik MGSU ◽  
2021 ◽  
pp. 429-437
Author(s):  
Gleb V. Martynov ◽  
Daria E. Monastyreva ◽  
Natalia S. Astafieva
Keyword(s):  
Composite Materials ◽  
Adhesive Bonding ◽  
High Strength ◽  
Test Point ◽  
Design Stage ◽  
Test Cycle ◽  
Thermal Tests ◽  
Adhesive Compound ◽  
Short Time ◽  
Cold Chamber

Introduction. Pultruded fiberglass can be called the material of the future due to its properties — high strength, low weight, resistance to aggressive environment. Important aspects for the development of composite materials are surface treatment methods and methods of connecting structural elements. Glue compound has proven itself as the most effective, but there remains a need to conduct studies of its durability. The method of accelerated cyclic thermal tests allows to determine the expected changes in the strength of adhesive bonding in a short time. Materials and methods. Samples, which are three glued plates of SPPS fiberglass construction, were processed in a climate chamber and after each cycle they were tested on a GRM-1 machine. One climatic test cycle included being in a chamber with high humidity and temperature and then moving into the cold chamber. The specimens were tested prior to spalling, and the resulting disruptive stresses were recorded. The last test cycle corresponded to five years of operation of the structure. Results. The tests of the samples showed a significant change in the characteristics of the compounds over time. In the first two years of operation, a decrease in strength of 25 % is expected. The last characteristic test point, corresponding to five years, showed a drop to 60 % of the initial characteristics. Conclusions. The results should be considered at the design stage of supporting structures that are not protected from contact with the external environment. The factors of strength reduction after 100 years may be included in the regulatory documents for the calculation of especially important structures.

scholarly journals The Strength Analysis of Hybrid (Bolted and Bonded) Single Lap joints for Composite Materials

2019 ◽  
Vol 8 (12) ◽  
pp. 4689-4692
Keyword(s):  
Composite Materials ◽  
Adhesive Bonding ◽  
Weight Ratio ◽  
High Strength ◽  
Lap Joints ◽  
Strength Analysis ◽  
Tightening Torque ◽  
Hybrid Joint ◽  
High Fatigue ◽  
Mechanical Fastening

The two joining techniques i.e. adhesive bonding and mechanical fastening combined are termed as hybrid joints. These kinds of joints mix the benefits of each the joining ways. The composite materials are used in structures at larger extend because of its properties like high strength to weight ratio, high fatigue resistance, high impact strength etc. The paper evaluates the mechanical behavior of Hybrid joint using composite as adherents subjected to tensile loading. The joint was observed to fail in two stages. Initially because of failure of adhesive and later by the failure of the bolt. The different parameters like overlap length, bolt size, tightening torque and adhesive thickness were studied and the significant factor were found to be overlap length, bolt size and tightening torque

scholarly journals Dimensional Variations of General Curved Composite Parts

2008 ◽  
Vol 41-42 ◽  
pp. 377-383
Author(s):  
Chen Song Dong
Keyword(s):  
Composite Materials ◽  
Process Development ◽  
Closed Form Solution ◽  
Weight Ratio ◽  
Tolerance Analysis ◽  
High Strength ◽  
Form Solution ◽  
Design Stage ◽  
Early Design Stage ◽  
Manufacturing Assembly

With the increasing demands of energy efficiency and environment protection, composite materials have become an important alternative for traditional materials. Composite materials offer many advantages over traditional materials including: low density, high strength, high stiffness to weight ratio, excellent durability, and design flexibility. Despite all these advantages, composite materials have not been as widely used as expected because of the complexity and cost of the manufacturing process. One of the main causes is associated with poor dimensional control. General curved composite parts are often used as the structural components in the composite industry. Due to the anisotropic material nature, process-induced dimensional variations make it difficult for tighttolerance control and limit the use of composites. This research aims to develop a practical approach for the design of general curved composite parts and assembly. First, the closed-form solution for the process-induced dimensional variations, which is commonly called spring-in, was derived. For a general curved composite part, a Structural Tree Method (STM) was developed to divide the curve into a number of pieces and calculate the dimensional variations sequentially. This method can be also applied to an assembly of composite parts. The approach was validated through a case study. The method presented in this paper provides a convenient and practical tool for the dimensional and tolerance analysis in the early design stage of general curved composite parts and assembly, which is extremely useful for the realization of affordable tight tolerance composites. It also provides the foundation of Integrated Product/Process Development (IPPD) and Design for Manufacturing/Assembly (DFM/DFA) for composites.

COMPARATIVE CHARACTERISTICS OF PHYSICAL AND MECHANICAL PROPERTIES OF COMPOSITE MATERIALS AND HIGH-STRENGTH STEEL 30FGSN2A

2020 ◽  
Author(s):  
I.R. Antypes ◽  
◽  
V.V. Zaitsev ◽  
Keyword(s):  
Composite Materials ◽  
High Strength Steel ◽  
Critical Stress ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Aviation Industry ◽  
Specific Strength ◽  
Aircraft Landing ◽  
Carbon Plastics ◽  
Aircraft Landing Gear

Currently, the use of composite materials is increasingly used in various areas of the national economy, including the aviation industry. The materials of this article are devoted to the study of the use of composite materials for the manufacture of aircraft landing gear in comparison with the traditionally used brand of steel. As a result of the work carried out, it was found that the slope made of carbon fiber showed a critical stress twice as high as its design made of 30xgsn2a steel. In addition, carbon plastics are superior to high-strength steel in terms of specific strength, stiffness, and tensile strength.

Product Modeling, Evaluation and Validation at the Detailed Design Stage

2011 ◽  
Author(s):  
Cristian Iorga ◽  
Alain Desrochers
Keyword(s):  
Product Development ◽  
Design Process ◽  
Design Stage ◽  
Product Modeling ◽  
Specific Product ◽  
Development Processes ◽  
Product Variation ◽  
Process Methodology ◽  
Capstone Projects ◽  
Short Time

The expansion of the markets corroborated with product customization and short time to launch the product have led to new levels of competition among product development companies. To be successful in the globalization of the markets and to enable the evaluation and validation of products, companies have to develop methodologies focused on lifecycle analysis and reduction of product variation to obtain both quality and robustness of products. Keywords: Modeling, Evaluation, Validation, Design ProcessThis paper proposes a new design process methodology that unifies theoretical results of modeling stage and empirical findings obtained from the validation stage. The evaluations and validations of engineering design are very important and they have a high influence on product performances and their functionality, as well on the customer perceptions.Given that most companies maintain the confidentiality of their product development processes and that the existing literature does not provide more detailed aspects of this field, the proposed methodology will represent a technical and logistical support intended for students or engineers involved in academic as well as industrial projects.A generic methodology will be refined based on a new approach that will take into consideration the specification types (quantitative or qualitative), the design objectives and the product types: new/improved, structural/esthetic. Hence the new generic methodology will be composed of specific product validation algorithms taking into account the above considerations. At the end of this paper, the improvements provided by the proposed methodology into the design process will be shown in the context of the engineering student capstone projects at the Université de Sherbrooke.

JESSOP JS17Cr-4Ni

Alloy Digest ◽  
1982 ◽  
Vol 31 (7) ◽  
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Food Processing ◽  
Precipitation Hardening ◽  
High Strength ◽  
Heat Treating ◽  
Steel Company ◽  
Lower Strength ◽  
Nickel Copper ◽  
Short Time

Abstract JESSOP JS17Cr-4Ni is a martensitic, precipitation-hardening chromium-nickel-copper stainless steel. It provides an excellent combination of high strength and hardness, short-time low-temperature precipitation hardening and good mechanical properties at temperatures up to 600 F (316 C). Its corrosion resistance is quite good but inferior to lower strength grades produced for corrosion-resistance applications. JS17Cr-4Ni is used widely for critical applications in the aerospace, chemical, food processing and other industries. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and fatigue. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SS-412. Producer or source: Jessop Steel Company.

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.

FEATURES OF APPLICATION OF SMALL RECONNAISSANCE ROBOT

2019 ◽  
pp. 29-38 ◽  
Author(s):  
R. Zinko ◽  
P. Kazan ◽  
D. Khaustov ◽  
O. Bilyk
Keyword(s):  
Mathematical Model ◽  
Armed Forces ◽  
Climatic Conditions ◽  
Design Stage ◽  
Experimental Sample ◽  
Single Trial ◽  
Test Cycle ◽  
Military Equipment ◽  
The Mathematical Model ◽  
Human Losses

A small intelligence robot (SSR) is a special military intelligence means. It is used to obtain information about the enemy - the collection of intelligence, the search for targets and target indication, observation of the situation, etc. The use of a small intelligence robot is assumed in various natural and climatic conditions: in temperate terrain, on soils with low bearing capacity, at low temperatures, in the desert, on sandy and marshy soils, on rocky soils, in elevated temperature and dustiness of air, and also in conditions highlands In the article an overview of modern developments of remotely controlled robotic military complexes, principles of their construction and perspective directions of development in the armed forces are reviewed. The issues of robotization of existing weapons and military equipment are considered. Every sample of a SSR used in combat action must possess all combat characteristics at once in an optimal ratio between them, ensuring its maximum effectiveness. Ignoring any of the properties or enhancing one property at the expense of others will not enable the full realization of the small surveillance robot. It is reasonable to select the relevant properties at the design stage, using the possibilities of mathematical modeling. The set of tactical and technical characteristics of the SSR allowed forming this. Its characteristics determine the scope and possibilities of application. The mathematical model of the SSR motion is written in the Matlab Simulink environment. Recorded mathematical model of SSR motion, formed single test cycle and input data allowed to conduct computer simulation of motion in possible conditions of operation of small surveillance robot.The single trial cycle presented contains a set of individual sites and reproduces the testing test cycle of a real polygon. On the basis of the developed tactical and technical characteristics of the SSR, the experimental sample was made. An example of the use of SSR for the intelligence of the settlement and at keeping the node of barriers has been provided. The efficiency of performing intelligence units’ tasks and reducing the risk of human losses are shown.

scholarly journals Defects and uncertainties of adhesively bonded composite joints

2021 ◽  
Vol 3 (9) ◽  
Author(s):  
Sadik Omairey ◽  
Nithin Jayasree ◽  
Mihalis Kazilas
Keyword(s):  
Composite Materials ◽  
Composite Structures ◽  
Production Efficiency ◽  
Adhesive Bonding ◽  
Detection Methods ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Adhesively Bonded Joints ◽  
Wide Range ◽  
Bonded Composite

AbstractThe increasing use of fibre reinforced polymer composite materials in a wide range of applications increases the use of similar and dissimilar joints. Traditional joining methods such as welding, mechanical fastening and riveting are challenging in composites due to their material properties, heterogeneous nature, and layup configuration. Adhesive bonding allows flexibility in materials selection and offers improved production efficiency from product design and manufacture to final assembly, enabling cost reduction. However, the performance of adhesively bonded composite structures cannot be fully verified by inspection and testing due to the unforeseen nature of defects and manufacturing uncertainties presented in this joining method. These uncertainties can manifest as kissing bonds, porosity and voids in the adhesive. As a result, the use of adhesively bonded joints is often constrained by conservative certification requirements, limiting the potential of composite materials in weight reduction, cost-saving, and performance. There is a need to identify these uncertainties and understand their effect when designing these adhesively bonded joints. This article aims to report and categorise these uncertainties, offering the reader a reliable and inclusive source to conduct further research, such as the development of probabilistic reliability-based design optimisation, sensitivity analysis, defect detection methods and process development.

Thermal Property Evaluation of Chilled Aluminum-Alumina MMC

2015 ◽  
Vol 1101 ◽  
pp. 79-82
Author(s):  
B.C. Suresh ◽  
S.B. Arun
Keyword(s):  
Thermal Expansion ◽  
Composite Materials ◽  
Thermal Property ◽  
Coefficient Of Thermal Expansion ◽  
Matrix Material ◽  
High Strength ◽  
Stir Casting ◽  
Al Alloy ◽  
Industrial Growth ◽  
Property Evaluation

Now a day’s composite materials are taking very important role in industrial growth. Composite materials are widely used in Automobiles, aerospace, submarine and also in other major fields, due to their special characteristics like light weight, high strength, stiffness, corrosion resistance. The determination of Coefficient of Thermal Expansion (CTE) of MMCs is important to aid its usage in high temperature environment as in the case of automobile combustion chamber. In these applications the stability of the composites over a long period of operation is a critical design considerationPresent work deals with the thermal property evaluation of the Al alloy / alumina metal matrix composite developed using the Stir Casting with chilling route technique. LM 26 Al alloy is being selected as the matrix material as it is a potential alloy for automotive piston applications. Al alloy / alumina MMCs was cast under end chilling technique by dispersing the reinforcement from 6 to 12 wt% the steps of 3% to study the variation in its thermal properties. At the same time chill material is also changed (Copper and MS) for different composition of MMCs cast to study the thermal behavior variations. After casting the required MMC, test specimens were prepared as per the standards to conduct thermal conductivity (K) tests and coefficient of thermal expansion (CTE) tests. Above tests were repeated for different composites containing different weight % of dispersed cast using different chills.

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