Authors: Akmal Raka Pamungkas, Tjokorda Gde Tirta Nindhia, I Wayan Surata, Tjokorda Sari Nindhia, Zdenek Knejzlik, Tomas Ruml
Abstract: The cocoon of Antheraea pernyi was grown in the laboratory with tropical artificial conditioning. The caterpillar was fed with Lantana camara leaf. They are 3 protocols provided to yield single fiber from the cocoon. The first protocol developed in this work was based on the single fiber drawing directly from the live caterpillar during cocoon stage establishment (forcibly silking). The single fiber was gently pulled and rolled up manually. The second protocol was conducted by degumming the cocoon with boiling in 5%NaoH solution. The cocoon was boiled in 5% NaOH solution and gently stirred. When the fiber was found detached from the cocoon, the boiling process was stopped, and the fiber obtained was washed with water and dried in the oven. The third protocol was simple boiling of the cocoon with water and gently stirring until the cocoon disintegrated to become a fiber. The fiber obtained was washed and dried in the oven. The first protocol by forcibly silking produced fiber with highest tensile strength of average value of 149.251 MPa. The other protocols introduced in this work resulted in lower tensile strength. Alkali treatment provided average tensile strength of 43.833 MPa and boiling in water resulted in tensile strength 52.571 MPa.
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Authors: Saif M. Abbas, Ghanim Sh. Sadiq, Muhammed Abdul Sattar
Abstract: This study used the tensile and fatigue test to find the properties of composite material used to fabricate a prosthetic socket with below knee amputation using an excluding air technique. The composite materials consisted of eight layers of carbon-fiber for first socket and eight layers of perlon for second socket of below knee amputation. This study was conducted on a patient have 45years old of height 164cm and weight95kg were measured, and the results showed that the ultimate stress (Ϭult) and yield stress (Ϭy) for eight layers of perlon was39 MPa and 36 MPa, while for eight layers of carbon-fiber was 135 MPa and 121 MPa. The fatigue limit for eight layers of perlon was 15 MPa and for eight layers of carbon-fiber was 90 MPa. The value of pressure on the internal wall of the prosthetic socket was measured by F-socket sensor between stump and socket for four position; this data is anterior =210kPa, lateral=313kPa, posterior=225kPa and medial=180kPa. From mechanical properties and ANSYS workbench 14.5software, the safety factor for below knee socket with eight layers of carbon-fiber is (1.35) which is acceptable for socket design. The safety factor for below knee socket with eight layers of perlon is (0.22) which is failure.
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Authors: Ali Abdulmohsin Khamees, Waleed Ali Tameemi, Osama Mohaymin Al Qassag
Abstract: This research is an experimental study on the fresh-state properties as well as the mechanical behavior of structural lightweight concrete (SLWCs) that made from recycled low-strength clay bricks (RLSCB). The test program includes testing ten mixtures of SLWCs with a target compressive strength of (35 – 40 MPa) and a target air density less than 1900 kg/m3 in addition, three mixtures of normal weight concrete (NWCs) of target compressive strength equal to 37.5 MPa were used for comparison purposes. For each mix of the fresh-status measurements, including slump, density, the air content and the temperature, a number were carried out. Furthermore, the mechanical performance for both SLWCs and NWCs under compressive, flexural and tensile stresses were conducted. The results show that structural lightweight concrete could be produced using recycled low-strength bricks as coarse aggregates with a reduction in dry density equal to 22%. Moreover, the reported results indicate that the compressive strength, splitting tensile strength, modulus of rupture and elastic modulus of elasticity of SLWCs were lower those for NWCs by about 5%, 14.5%, 16.5% and 17.4%, respectively. Finally, correlations between compressive behavior and flexural behavior; compressive behavior and tensile performance; flexural behavior and tensile performance for SLWCs are proposed in this study.
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Authors: Mochamad Asrofi, Sujito Sujito, Edi Syafri, S.M. Sapuan, R.A. Ilyas
Abstract: Biocomposite based tapioca starch (TS) and sugarcane bagasse cellulose nanofibers (SBCN) was made through casting method. SBCN was prepared by chemical and ultrasonication process. It was successfully displayed by transmission electron microscope (TEM) in range 20 - 45 nm. Meanwhile, particle size analysis (PSA) also supported the distribution diameter of SBCN for 59.75 ± 10.84 nm. SBCN and glycerol were used as reinforcement and plasticizer, respectively. The amount concentration of SBCN was varied from 0 to 8 wt%. Biocomposite was characterized by using scanning electron microscopy (SEM) and tensile test. SEM image displays SBCN is in good interfacial bonding with the matrix. The highest tensile strength of biocomposite was in TS/4SBCN sample for 20.84 MPa. These results showed that SBCN fiber become potential candidate as reinforcement in biocomposite application.
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Authors: Nur Nabila Mohd Nazali, Nur Ani Aniqah Anirad, Nor Fazli Adull Manan
Abstract: This paper focuses on the characterized of the mechanical properties and hyper elastic behavior of lab made skin. Bovine Serum Albumin (BSA) combined with gelatin as a base. BSA is a plasma lead concentrations or heparin plasma which is separated from blood sample and it is not associated with significant changes in iron or hemoglobin concentrations. In general, the gelatin is widely used as the best material for skin substitution since it exhibits the characteristic of human skin. However, the lab made skin layer was made of non-halal type gelatin (Type B). The methodology process started by adding the BSA and using the type A gelatin to carry out the mechanical properties and hy-per elastic behavior of halal lab made skin layer. A uniaxial tensile test standard that being used in this study is ASTM D412. The raw data (Load-Extension) from computational was plotted on graph stress-strain. The numerical approach such as Mooney-Rivlin model and Yeoh’s model were selected to analyze a stress-stretch of composition gelatin and BSA. From the results Mooney-Rivlin model, the con-stant, C1 is in the range of (0.0187-0.0658) MPa and C2 is in the range of (0.0628-0.0737) MPa. Meanwhile the constant, CP for Yeoh model is in the range of (0.0748-0.0861) MPa. As a conclusion, the composition of gelatin and Bovine Serum Albumin is a best combina-tion as it increases the strength of the lab made skin layer. Therefore, the most suitable composition is 10 wt.% of gelatin and Bovine Serum Albumin.
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Abstract: In this study, the tensile and flexural strengths of cottonseed hull reinforced epoxy composites were investigated. Specimens were made using a stainless steel mold. A hand lay-up process was used to make the composite material, and three kinds of materials were made: unreinforced epoxy, raw cottonseed hull reinforced composite, and grinded cottonseed hull reinforced composite. The fiber content of all composites is 15 wt%. Tensile and flexural test were performed with universal testing machine. The result shown that Tensile and flexural strengths of grinded cottonseed hull reinforced composites were found to be the highest.
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Authors: S.R. Ranganatha, M Shantharaja
Abstract: In this research work an effort has been made to study the tensile behavior of boron carbide and copper coated short basalt fiber reinforced with Al2014 based hybrid composites are prepared by stir casting technique. To avoid the interfacial reactions between basalt fiber and matrix Al2014 alloy the fibers are coated with copper using copper sulphate solution by electroless deposition method.The coated fiber was observed by scanning electron microscopy (SEM). It has been clearly revealed the uniform deposition of copper on the surface of fiber and tensile behavior of Hybrid composites was increased with increase in the wt% of reinforcements. At 6% boron carbide and 8% copper coated basalt fiber shows maximum tensile property.
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Authors: Wikan Jatimurti, Boby Alexander, Alvian Toto Wibisono
Abstract: This research is aimed to get a better understanding on the effort of reducing the porosity level in aluminum alloys. The degassing process (2, 5 and 8 minutes) is done to reduce the hydrogen content in liquid aluminum and cooling rate modifications (13 °C / min, 20 °C / min and 26 °C / min) was performed to reduce the porosity by reducing the size of Dendrite Arm Spacing (DAS). The casting method used in this research is sand casting and raw materials were melted using an electric furnace at 720 °C. The microstructural images showed the DAS size are decreased by size from 137.3 μm to 87.58 μm obtained from cooling rates of 13 °C / min and 26 °C / min respectively. In the other hand, the level of porosity is also decreased from 3.58% at 2 min degassing and the cooling rate of 13 °C / min to 1.8% at 5 min degassing and 26 °C / min cooling rate. Furthermore, the tensile test results show that the value of tensile strength increases when the DAS size and porosity level are smaller. The highest ultimate tensile strength value is 105.9 and the lowest is 70,53 MPa.
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Authors: Pavel Srb, Martina Syrovátková, Petr Kulhavý, Blanka Tomková
Abstract: This article deals with assessment of mechanical properties and possible technical usability of flax prepreg composite materials. Mechanical properties of materials are the decisive factor for selection of their suitable industrial application. The main step was to describe the process of acquiring basic mechanical properties of one layer. Then, these properties were used for creation of a numerical model of a primary laminate and subsequently for modeling a multilayered composite. The performed FEM model has been verified based on the experimentally tested samples in tensile and flexural loading.
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Authors: Suriyanti Kuddus, Mohammad Sukri Mustapa, Mohd Rasidi Ibrahim, Shazarel Shamsudin, Muhammad Irfan Ab Kadir, Mohd Amri Lajis
Abstract: This research aims to investigate the effect on tensile strength of the recycled chip AA6061 aluminium alloy metal by using powder metallurgy method. Material used is recycled aluminium Chip AA6061 and Al powder. The recycled AA6061 chips mixed together with various compositions of Al powder content were fabricated to form a specimen by hot compaction technique. The compaction using hot pressed at 30 tons with holding time of 60 minutes. The final product was analyzed by tensile test shown the specimen A5 have higher ultimate tensile strength (UTS) 156.404 MPa and yield strength (YS) at 107.399 MPa. Scanning Electron Microscopy (SEM) was conducted to observe the microstructure of fracture surface existing on the tensile specimens.
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