Influence of B4C on oxidation resistance of PSN/borosilicate glass-B4C field-based repair coating of C/C aircraft brake materials at 700–900 °C

The paper is focused on the research of the cyclic loading of hybrid adhesive bonds based on eggshell microparticles in polymer composite. The aim of the research was to characterize the behavior of hybrid adhesive bonds with composite adhesive layer in quasi-static tests. An epoxy resin was used as the matrix and microparticles of eggshells were used as the filler. The adhesive bonds were exposed to cyclic loading and their service life and mechanical properties were evaluated. Testing was performed by 1000 cycles at 5-30% (165-989 N) and 5-70% (165-2307 N) of the maximum load of the filler-free bond in the static test. The results of the research show the importance of cyclic loading on the service life and mechanical properties of adhesive bonds. Quasi-static tests demonstrated significant differences between measured intervals of cyclic loading. All adhesive bonds resisted 1000 cycles of the quasi-static test with an interval loading 5-30%. The number of completed quasi-static tests with the interval loading 5-70% was significantly lower. The filler positively influenced the service life of adhesive bonds at a higher amount of quasi-static tests, i.e., the safety of adhesive bonds increased. The filler had a positive effect on adhesive bonds ABF2, where the strength significantly increased up to 20.26% at the loading of 5-30% against adhesive bonds ABF0. A viscoelasticity characteristic (creep) of the adhesive layer occurred at higher values of loading, i.e., between loading 5-70%. The viscoelasticity behavior did not occur at lower values of loading, i.e., between loading 5-30%.

Quasi-Static Tests of Hybrid Adhesive Bonds Based on Biological Reinforcement in the Form of Eggshell Microparticles.

This paper describes the research gyrocopter and presents the methodology of numerical calculations for this type of research objects. There are also the results of an ANSYS Fluent three-dimensional simulation of an airflow around a gyrocopter, excluding an airflow around its main rotor and propeller blades. The calculations enabled basic aerodynamic characteristics. The analysis of the numerical calculations focuses on the impact of gyrocopter individual sections like a fuselage, tail, tail boom, etc., on aerodynamic forces and moments, as well as coefficients of aerodynamic forces and moments. The research scope covers an angle of attack α ranging between -20° and 25° at a sideslip angle equal to 0.

/pdf/numerical-analysis-of-the-influence-of-particular-autogyro-4psdzmdw80.pdf

Numerical analysis of the influence of particular autogyro parts on the aerodynamic forces

The surface condition effect on adhesion and corrosion resistance of carbon steel/chlorinated rubber/artificial sea water systems

An adhesive bonding technology represents a prospective method of diverse materials connecting. Polyurethane (PUR) adhesives namely are used in an area of the adhesive bonding of wood and cellulose - based products. They gradually substitute formaldehyde-based adhesives. A higher reactivity of isocyanates with any compound having moving hydrogen namely, i.e. e.g. water, etc. is a significant disadvantage. An elimination of this negative factor is possible by adding a filler, e.g. PUR recyclate - based. The aim of the research is to determine an adhesive bond strength of the PUR adhesive modified with microparticles of crushed PUR foam (waste from a building - an insulation material). Improving of a tensile lap-shear strength and a material recyclation of the PUR foam are expected aims. Also a reduction of the adhesive price is a secondary output. Results of mechanical tests were supported by conclusions from a scanning electron microscopy (SEM) analysis with an aim to evaluate the interaction between the adhesive and the recycled filler. A diffusion of the adhesive into a wooden surface would occur at the wooden test samples and so mechanical properties of the modified adhesive would not be determined. This reason led to the research on the modification of the PUR adhesives LEAR D4, PP-6a17 and PP-7a within the adhesive bonded metal bond (a structural carbon steel S235J0). The research results proved a positive influence of the modification of the PUR adhesive with the microparticles of the PUR recyclate. The tensile lap-shear strength was increased. Results of SEM analysis proved a good wettability.

Research on Influence of Polyurethane Adhesive Modified by Polyurethane Filler Based on Recyclate

The aim of this paper is to determine the effect of arrangement of fibreglass fabric plies in a polymer composite on adhesive joint strength Based on the experimental results, the real effect of plies arrangement and their most favourable configuration with respect to strength is determined The experiments were performed on 3 types of composites which had different fibre orientations The composites had three plies of fabric The plies arrangement in Composite I was unchanged, in Composite II the central ply had the 45° orientation, while in Composite III the outside ply (tangential to the adhesive layer) was oriented at 45° Composite plates were first cut into smaller specimens and then adhesive-bonded in different combinations with Epidian 61/Z1/100:10 epoxy adhesive After stabilizing, the single-lap adhesive joints were subjected to shear strength tests It was noted that plies arrangement in composite materials affects the strength of adhesive joints made of these composites between the values of the strength of the confidence level of 095 The statistical analysis of the results also showed that there are no statistical significant differences in average values of surface free energy (095 confidence level)

https://iopscience.iop.org/article/10.1088/1742-6596/842/1/012074/pdf

Experimental research and statistic analysis of polymer composite adhesive joints strength

The following paper analyses selected problems regarding the impact of technological parameters and the type of adherend material on the strength of adhesive-bonded steel sheet joints. The subject of the test was a single-lap adhesive joint of S235JR steel sheet. Joints were formed on two types of substrates: with or without corrosion products on the surface. The surface of steel sheet adherends was pre-treated with three cleaning solutions: acetone, Wiko industrial degreasing agent and Cortanin F anti-corrosion agent, depending on the state of the surface. Adhesive joints were formed with Epidian 53/ET/100:15 epoxy adhesive. The formed joints were subjected to one of three ageing variants: 14 days, two months and 3 months, which were followed by destructive testing to determine the shear strength of joints. The analysis of results obtained in the tests indicates that the strength performance of adhesive joints of corrosion-free adherends was characterised by higher values than in corroded steel sheets, regardless of ageing time.

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The impact of selected technological and material parameters on the strength of adhesive steel sheets joints

The paper presents the analyzes of the pre-rotation engine loads in the Taurus autogyro manufactured by Aviation Artur Trendak from Poland. Based on the NACA-9 H-12 airfoil characteristics of the drag coefficient, on which the rotor blade was made, forces acting on the rotor during pre-rotation have been calculated. The paper presents the characteristics of the drag coefficient as a function of angle of attack for Re = 1,800,000 and Re = 2,600,000. For the speed range of 0 to 400 rpm torque resulting from the drag forces and the power required to drive the rotor were calculated.

Analysis of the pre-rotation engine loads in the autogyro

Suspected Endodontic Failure in a Patient with Cleidocranial Dysplasia: A Case Report.

In April 2017 at Hannover Messe presented electric-hydrogen bus produced by Ursus. It is already the third generation of electric buses introduced on the market by the manufacturer from Lublin. The article contains a thorough description of three generations of electric buses. It presents the most important technologies influencing the performance of each generation. Conducted in a continuous research and development activities result in expanding the autonomy of the next generations. Ursus company also develops technology for rapid maintenance-free charging systems for electric buses using the pantograph. In the article there was presented a comparison of selected parameters of each generation of electric buses. Article ends with the review of their advantages and disadvantages compared to the conventional power drivetrains based on Diesel engines.

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Dariusz Kasperek

Papers

Experimental research and statistic analysis of polymer composite adhesive joints strength

The impact of selected technological and material parameters on the strength of adhesive steel sheets joints

Analysis of the pre-rotation engine loads in the autogyro

Suspected Endodontic Failure in a Patient with Cleidocranial Dysplasia: A Case Report.

Developed generations of electric buses produced by Ursus