Papers by Keyword: Mechanical Test

Abstract: This work focuses on the design and the study of mechanical behavior of new adobe clay bricks material made from local ecological materials for use in construction. The hydraulic binder used is a clay mineral material from the Sibang district in Gabon, and the biomass consists of sawdust from tropical wood species (okoume) combined with additives such as sugar cane molasses and cassava starch. The sawdust comes from okoume, where the selected protocol is based on their availability and widespread use locally. Preleminary tests done on clay show detailed analyses using laser granulometry, chemical analysis of major elements in total rock, X-ray diffraction on total rock and oriented samples (normal and heated to 550°C and ethylene glycol), infrared spectroscopy, cation exchange capacities, and scanning electron microscopy. The mixture of sawdust from okoume, padouk, azobe specie and 85% Sibang clay allowed for the design of bricks with quality facades. The respective compression strength tests resulted in 6.44 MPa, 3.15 MPa and 3.13 MPa, where the mixture containing the okoume sawdust showed a resistance, of 6.44 MPa, two times higher than the others. The adobe bricks incorporating sawdust from okoume, padouk and azobe woods are in compliance with the French standard for compressed earth blocks. The sawdust-wood mixture combined with clay is an ecological material and an alternative to the use of traditional concrete blocks in Gabon.

Abstract: This study illustrates how the mechanical characteristics of a composite may be altered by adding powdered natural fillers such as fish scales or coconut shells. Hand lay-up approach has been used to create the Jute/Basalt hybrid composite with fillers. The epoxy and hardener were combined at a weight ratio of 10:1, and then the natural fillers were added at varied percentages of 3%, 6%, and 9%. The ASTM standards were used for the mechanical test. Fish scale filler has greater tensile and flexural strengths than coconut shell powder, but the latter's impact strength grows with increasing amounts of filler. Jute/basalt composites were also subjected to a water absorption test, the results of which showed that those containing fish scale powder absorbed significantly less water than those containing coconut shell powder.

Abstract: In this work, we propose the stabilization of soft sea sand by an epoxy composite solidifier, which can be extremely beneficial in the fields of national defense, rescue engineering, and traffic emergency support under complex conditions. The effects of material ratio, curing time, curing temperature, and moisture content on the mechanical performance (compressive strength, bending strength, and splitting tensile strength) of solidified sea sand are investigated by indoor tests. The results indicate that the epoxy composite solidifier can rapidly enhance the mechanical performance of sea sand, thereby improving the beach trafficability and facilitating traffic emergency support. The strength of solidified sandy soil increases with the increase in curing time and temperature or with the decrease in moisture content. Furthermore, the epoxy composite solidifier exhibits good solidification capability under low temperatures and saturated moisture content. Keywords: epoxy resin; solidifier; sea sand; mechanical test

Abstract: A stress softening known as the Mullins effect is observed usually in rubberlike material after the first load. This paper describes an experimental test method for defining the nonlinear properties of rubber materials used for finite element analysis. Experimental observations have shown that the Mullins effect induces a permanent set and some anisotropy. To test the Mullins effect the mechanical preconditioning is suggested to stabilize the properties of rubber material. A stress-strain curve will change significantly when the rubber material is strained greater than the previous stabilized level. Therefore, material properties at maximum strain level are obtained to predict behavior of rubber products. To obtain the rubber material constants used for finite element analysis to understand the characteristics of automotive rubber parts, mechanical properties tests such as uniaxial tension, equ-biaxial tension and pure shear tests are required. When the load was repeatedly applied to the rubber specimen, the stress-strain relationship was greatest in the first and second cycles, and the larger the strain range, the more the stress was reduced. The material constants were obtained using the stress-strain data after the rubber specimen was stabilized. The value of stiffness decreased as the maximum strain range increased. The static stiffness of an automotive engine mount is calculated by nonlinear finite element analysis using the experimentally determined material constants and compared with the experimental results considering the mechanical preconditioning effect resulting in a good correlation.

Abstract: Recently, ceramic material has become a main object of scientific interest especially in dental material. The advance of dental materials technology has led to use of zirconia-based ceramics for composite filler. In this study, composite filler has been synthesized from natural zircon sand through geopolymerization method. Composite prototype were made with different filler volume to evaluate mechanical properties including hardness number and diametral tensile strength. Samples divided into two groups with 50 wt% filler volume (group A) and 75 wt% filler volume (group B) which 3 samples for each group. The surface micro hardness of each group tested by Leco M-400-H1 vickers microhardness testing machine and for diametral tensile strength tested using universal testing machine (Lloyd) with crosshead speed of 1,0 ± 0,25 mm/min. The data were analyzed using independent sample t-test. The results showed that the average of hardness number on group A was 13,8 VHN while for group B was 24,1 VHN. The average of diametral tensile strength for group A was 20,461 MPa and 27,689 MPa for group B. Statistical result showed that the value (P<0,05). The conclusion, there is a signifficant difference on the result of hardness test between group A (50 wt% filler volume) and group B (75 wt% filler volume) and also on diametral tensile strength test.

Abstract: Mushroom growing media waste (MGMW) is the media waste after mushroom plants are harvested. In this research, we try to reuse MGMW as a material for composite particle board. The physical properties of the composite were tested using density and moisture content measurement. We also did the measurement for thickness swelling after immersion in water, the strength of absorption water, internal bonding. The mechanical test was conducted to know the modulus of elasticity, modulus of rupture and screw holding power properties. Impact and pressure was done for the optimum composition. The optimum composition, particle board is 75% MGMW + 24% polyester resin + 1% catalyst Mekpo (methyl ethyl ketone peroxides), and 60% MGMW + 39% (50% urea +50% starch) + 1% PVC glue. It is suitable for physical and mechanical test and accordance with SNI 03-2105-2006 and JIS A 5908-2003. The microstructure of MGMW was observed using Scanning Electron Microscope (SEM) shows the grain of a composite particle board is firmly integrated.

Abstract: Samples from high compressibility powders (Ancorsteel 1000B) obtained by pressing at different pressures and sintering at 1150 °C, with (IPASW) and without spring steel wire (Φ = 0.5 mm) reinforcement (IPAS), coated and uncoated with zinc samples were selected for study of corrosion behaviour in salt spray and were subjected to mechanical tests (tensile strenght).

Abstract: In recent years, natural composite materials have replaced many conventional ones, such as metals and synthetic resin composites in many applications. This is due to the advantage of hybrid natural composite over the conventional materials. The natural composites are made up of both reinforcement and matrix materials which are obtained by the natural resources. Natural fibers reinforcement are strong, light weight, renewable, cheap, completely or partially recyclable, and biodegradable. In this work sisal and banana fibers have been used as the main reinforcing materials to increase the effectiveness of natural fibers. Cashew nut shell liquid (CNSL) resin is a natural resin that can be obtained from cashew nut. CNSL is essentially a mixture of phenol extracted from the shell of the cashew nut and is a good natural alternative to chemically derived phenol.

Abstract: For ensuring fuel consumption and pollution reduction, the researches made in the past decades considerable efforts to replacing steel with aluminum alloys in manufacturing auto bodies, or in naval transportation, because the promising weight saving. The researches consisted in general corrosion (the gravimetric index and the corrosion rate, Vcorr) and tensile tests (Rm, Rp_0.2 and A5) in correlation with microstructure analysis of heat treated Al-Mg-(Si) system samples alloy, in order to obtain the best corrosion resistance and high mechanical characteristics. The Al alloys in extrusion state were solution treated at 510 – 545oC for 10-60 minutes, quenched in water 30-50o C and artificial aging at 150, 180 and 210°C at different time of aging (1, respectively 3, 7 and 11 hours). After heat treatment the obtained alloys were corroded in solution of 53g NaCl + 1000 ml distilled water and boiled in these solutions for 8, 16 respectively 24 hours. The gravimetric index was determinate by mass loss measurements for all types of heat treatment conditions. After corrosion test, samples were prepared for optical microstructural analyzing and mechanical tested. We have compared the obtained results on Al-Mg and Al-Mg-Si alloys. Were established (i) the optimum heat conditions parameters for obtaining of highest values of mechanical characteristics and corrosion resistance and also (ii) was explained the structural evolution during age (precipitation) hardening for both systems.

Abstract: It is a common understanding that hot forging will improve the properties of a steel part in relation to when the same part is made by casting solely. A study has been performed where two crank pin disks of a particular steel alloy, one hot forged and the other cast, both in quenched and annealed condition, have been tested using a new innovative “eye”-specimen bending test. The used test procedure is described, and it is shown that the forged and the cast material will collapse and beak down in very different way in this test.