scholarly journals Corrugated Structure Reinforcing Aluminum Foam

2021 ◽  
Author(s):  
Massimo Durante ◽  
Luca Boccarusso ◽  
Antonio Formisano ◽  
Dario De Fazio ◽  
Antonio Viscusi ◽  
...  

Metal foams have a number of established niche market and potential applications under investigation due to their peculiarities including thermal, acoustic and mechanical properties at low weight. In order to produce structures resistant at high temperature and acting as barrier to the fire, metals with closed cells are often required, and one of the most consolidate manufacturing process for their production is the gas releasing particles decomposition in semisolids, by means of which a foam is created by a foaming agent dispersed into a precursor. In previous researches, the authors have investigated the possibility of foaming the aluminum starting by a precursor, placed between two skins consisting of steel grids, in order to obtain a sandwich structure at the same time of the foaming step. In line to continue on this topic and to improve the compression strength of the aluminum-foamed core, in this work the steel grid was used both as skins and as a corrugated skeleton inside the core. Different types of sandwich structures were manufactured, following some experimental tests executed to determine the optimal value of temperature and time to foam the precursor. Then, compression tests were carried out, in order to investigate the effectiveness of the proposed solution on the improvement of this mechanical behavior. The mechanical tests highlighted the increase of mechanical properties using this type of corrugated core.

2014 ◽  
Vol 600 ◽  
pp. 57-68 ◽  
Author(s):  
Patricia Luna ◽  
Caori Takeuchi ◽  
Edwar Cordón

This paper presents the mechanical properties measured on glued laminated pressed guadua samples. Experimental tests like shear parallel to fiber, tensile and shear perpendicular to fiber and flexural tests were carried out using three different types of adhesives: European Melamine Urea Formaldehyde, Colombian Melamine Urea Formaldehyde, and Polivinil Acetate humidity resistant. In order to study the behavior of the material in aggressive environmental conditions, half of the samples used in the mechanical tests were introduced in a temperature and humidity chamber for 45 days set to 45°C of temperature and 95% of relative humidity, usual environmental conditions in Chocó Colombia.The results showed that the highest values of mechanical strength were obtained for samples made with European Melamine Urea Formaldehyde. In addition, it was found that this adhesive was the one with better behavior under the aggressive environmental conditions simulated.


2018 ◽  
Vol 786 ◽  
pp. 319-324 ◽  
Author(s):  
Markku Kananen ◽  
Antti Järvenpää ◽  
Matias Jaskari ◽  
Kari Mäntyjärvi

Corrugated core panels contain a formed, corrugated core bonded between two skin sheets. These panels are typically used in applications, where a low weight is required with integrity in stiffness. This paper demonstrates the mechanical properties of a simple panel structure (SPS), constructed using strips of work-hardened, austenitic stainless steel (ASS) grade 1.4310 (type 301) with the yield strength (YS) of ~1200 MPa. The 0.5 mm thick strips were formed into a C-shape and subsequently laser welded together by lap joints to form a SPS. The thickness of the SPS was 50 mm. The bending tests for the SPS were carried out transverse and 45-degrees related to the orientation of the web sheet. The results showed that the SPS, as loaded in the transverse direction, has about the same bending stiffness prior yielding as that of the previously tested 6 mm thick, low carbon S355 plain steel sheets, but the SPS is three times lighter than 6mm thick plain steel sheet. Compared with a corrugated core panel made of an annealed ferritic stainless steel (SS-panel) with the YS ~ 250 MPa, the weight of the both panels are roughly the same, but the bending resistance of the SPS is 45% higher. Experimental tests also verified that the benefit in the stiffness is quickly reduced if the load direction differs from transverse. In the 45-degrees loading direction, the SPS and the SS-panel had almost the same bending strength. On the other hand, the SPS and the SS-panel stiffnesses are much better than that of the carbon steel (the YS ~ 300 MPa) panel (CS-panel) in the both loading directions – the SPS being twice as stiff as the CS-panel.


2021 ◽  
Vol 56 (5) ◽  
pp. 179-185
Author(s):  
Omar A. Amin ◽  
S. A. Hassan ◽  
M. A. Sadek ◽  
M. A. Radwan ◽  
Hany A. Elazab

Epoxy resins are thermoset polymers that consist of epoxide groups in their molecular structure. It shows many attractive characteristics like strong adhesion, excellent mechanical strength, low shrinkage, excellent insulator, excellent chemical stability for acidic and basic environments, and microbial resistance due to the presence of hydroxyl groups and ether bonds and its three-dimensional structure. Many of these characteristics can be modified by adding strong bindings in the polymeric chain to give more improved characteristics. This research aims to prepare a composite material using epoxy resin and different types of fillers to achieve resistance to high kinetic energy impact. Experimental work is focused on preparing cured epoxy resin samples by using diglycidyl ether of bisphenol A (DGEBA) resin with tertiary amine as a hardener. In order to obtain different samples with different properties, we add different types of fillers, then mechanical tests are used to measure the mechanical properties of the samples. The results have proved that fiberglass is the best filler added to epoxy resins to improve its mechanical properties.


2021 ◽  
Vol 2070 (1) ◽  
pp. 012234
Author(s):  
Yogeesha Pai ◽  
Dayananda Pai K ◽  
M Vijaya Kini

Abstract Polymer composites used in outdoor applications are exposed to environmental factors such as temperature and moisture which may affect the mechanical performance of the composites. In this study, the influence of moisture absorption on the mechanical properties of basalt-aramid/epoxy hybrid interply composites were evaluated. Two different types hybrid interply composites were taken for the investigation namely (301 A/03 B/301 A) and (451 A/03B/451 A). Composites were prepared using compression molding process and cut specimens were subjected to three different ageing environments for 180 days. Selected ageing conditions are, (i) ambient temperature ageing (ii) Sub-zero temperature ageing (−10°C) and (iii) Humid temperature ageing (40°C and 60% Relative humidity). Mechanical tests of the aged composites were carried out to analyse the behaviour of the composites. Moisture uptake of the specimens follow Fick’s law of diffusion with saturation absorption of 5.44%, 3.12% and 1.80% for ambient, sub-zero and humid specimens respectively. Results revealed that (301 a/03 B/301 a) aged composites possess higher mechanical properties compared to (451 a/03 B/451 a) aged composites. Highest reduction in properties were observed in ambient aged specimens followed by humid and sub-zero specimens. Scanning electron microscopy (SEM) was employed to observe the damage modes of the fractured specimens. Matrix deterioration, micro cracks and fibre fracture were the major types of failures observed in aged laminates.


2018 ◽  
Vol 68 (3) ◽  
pp. 302-308
Author(s):  
Magda Krasińska-Mazur ◽  
Wojciech Ryniewicz ◽  
Joanna Ryniewicz ◽  
Jolanta E. Loster

Regardless of the rapid development of various digital scanning techniques of oral tissues, gypsum remains the most widespread material used in the laboratory execution of almost all prosthetic restorations. The mechanical properties of different types of gypsum are affected by the amount and temperature of the water used to preparing the mass, as well as the method and speed of its mixing. The aim of the study was to compare the mechanical properties of type 2, 3 and 4 gypsum during crushing and breaking tests, depending on the way of preparing the mass. Material and methods. For each test, 60 plaster samples in the shape of a cylinder were prepared in two dimensions: 4x10 mm and 4x20 mm. The material used to make the samples were Stodent II (type 2) and Stodent III (type 3) from Zhermapol and Fuji Rock from GC (type 4). Gypsum was mixed by hand or by vacuum machine. Six groups of samples of 10 were obtained. After 1 week, when the samples were stored at room temperature, they were subjected to crushing and breaking tests on the INSTRON 3345 strength machine. Results. The results of compression tests and three-point fracture were analyzed statistically using the Statistica 13.1 software (StatSoft). The greatest strength both crushing and breaking showed samples of type 4 gypsum, the smallest - type 2 plaster cast. Significantly lower standard deviation was observed in the case of mixed gypsum with the use of a vacuum mixer. Conclusion. Gypsum models should be cast from vacuum mixed gypsum.


2017 ◽  
Vol 54 (4) ◽  
pp. 645-647
Author(s):  
Corneliu Druga ◽  
Radu Necula ◽  
Diana Cotoros ◽  
Roxana Miclaus ◽  
Angela Repanovici ◽  
...  

Most studies and experimental tests performed upon orthopaedic bone cements are related to their use in everyday conditions when usual wears are due to compression and fatigue. The present paper deals with some special situations occurred during the patient�s recovery after the surgery. The recovery activities and motions may induce different types of loads, like tensile, during stretching and relaxation techniques, especially in the joint insertion area. These situations are insufficiently researched, but they represent one of the main concerns of the medical staff involved in recovery and rehabilitation. Besides the study of mechanical properties for these special situations the paper proposes also a thermal analysis during preparation of the polymethylmethacrylate(PMMA) as it can be the trigger of serious health issues (necrosis, blood circulation problems, BCIS, etc.) due to the exothermic polymerization reaction. The monitoring method proposed for the temperatures developed during the polymerization may avoid the aforementioned issues.


Author(s):  
B. Sułkowski ◽  
G. Boczkal ◽  
P. Pałka ◽  
G. Mrówka-Nowotnik

To produce castings of titanium, nickel, zinc, copper and many other metal alloys, graphite molds can be used. Using graphite molds has many advantages which are no lubricate or coating layers are needed, high cooling rate, easy of production of complicated shapes. However, for good quality of castings there is needed a good quality of graphite with high mechanical properties and good heat transfer coefficient. Because of no room for manipulating of chemical composite of graphite molds, the most important factor influencing the properties of the molds is their production process. Thus, in the present study mechanical properties of two different type of graphite were investigated. There was graphite produced by different technological processes. One of the processes was a typical graphite production process from the isotropic coke, the second process was an electrolytic method production. Investigations included mechanical tests as well as the structure observations by scanning electron microscope. Chemical analysis was determined by Energy Dispersive X-ray Spectroscopy method additionally, phase analysis using the XRD method was performed. Mechanical properties were obtained by compression tests and three points banding tests at room temperature. It was found that the porosity of a graphite is the key parameter for good its mechanical properties. In addition, it was found that the mechanical anisotropy of graphite is the effect of the production method where the size and distribution of pores play an important role. Ill. 7. Ref. 9. 


2021 ◽  
Vol 880 ◽  
pp. 161-167
Author(s):  
Joaquin Humberto Aquino Rocha ◽  
Fernando Palacios Galarza

Waterproof additives and bonding agent mixtures are commonly employed in the setting up of render mortars. This practice often shows beneficial results, enhancing the properties of the common mortars. Yet, the use of these additives does not seem to have a direct effect on the mechanical properties of the mortars. This study thus aims to evaluate the influence of the use of waterproof and adhesion additives on the mechanical properties of render mortars. Based on their chemical composition, three different types of mortar admixtures were evaluated, using fourfold additive-mortar weight ratios: 0%, 1.5%, 3%, and 5%. Compressive and flexural strength tests were conducted after 28 days. The results showed a negative impact on the mechanical properties of the mortars. The lowest flexural and compression strength values reported are 1.52 and 4.57 (MPa), respectively. However, all compressive and flexural strength values lied within the limit range recommended by the “Mortars applied on walls and ceilings” construction code (i.e., ABNT NBR 13281). It is compulsory to continue the experimental tests to determine render mortars mechanical properties with higher waterproof additive-mortar weight ratios since higher ratios might produce mortars with non-allowed mechanical properties.


2019 ◽  
Vol 63 (3) ◽  
pp. 183-187
Author(s):  
Romany R. Moussa ◽  
Amer E. Ali ◽  
Ragab K. Abdel-Magied ◽  
Mohamed N. Elshiekh

The mechanical properties as well as microstructure of the ductile cast iron (DCI) are most likely affected by heat treatments. In this work, the mechanical properties of different heat treated of DCI alloy were investigated. Two heat treatment (HT) processes were conducted for DCI; austempering and quenching followed by lower tempering. The melted alloy of DCI was poured in Y-block, from which the specimens of the mechanical tests were prepared. Experimental tests were carried out to investigate the effect of these HT processes on the mechanical properties. A comparison between mechanical properties due to HT and as cast DCI are presented and discussed. The results showed that there is a difference in microstructure, homogeneity, wear rate and compression of DCI based on the conducted heat treatment.


2020 ◽  
Vol 986 ◽  
pp. 41-49
Author(s):  
Radka Pernicova ◽  
Tomas Kolomaznik

This document explains and demonstrates the influence of plasticizing additives on concrete – wet cured concrete with aggregate based on silicon carbide specifically. These special products have been designed for the foundry industry and have specific requirements for treatment in their early curing stage. The paper deals with the optimization of the currently used formula in order to increase their mechanical and surface properties by adding several different types of plasticizing additives and/or combinations thereof. Indicators of the measured characteristics have been mechanical tests, surface properties, and bulk density, which represented the SiC indicator of the mixture. With regard to the measured data, it can be stated that the effect of the plasticizing additive on special concrete with SiC aggregate have been considerable and depended very much on the type of additive used and its dosage, as the resulting mechanical properties differed by up to 40%.


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