Ariffin Ismail

Performance of Hybrid Steel Fibers Reinforced Concrete Subjected to Air Blast Loading

This paper presents the results of the experimental data and simulation on the performance of hybrid steel fiber reinforced concrete (HSFRC) and also normal reinforced concrete (NRC) subjected to air blast loading. HSFRC concrete mix consists of a combination of 70% long steel hook end fibre and also 30% of short steel hook end fibre with a volume fraction of 1.5% mix. A total of six concrete panels were subjected to air blast using plastic explosive (PE4) weighing 1 kg each at standoff distance of 0.3 meter. The parameters measured are mode of failure under static and blast loading and also peak overpressure that resulted from detonation using high speed data acquisition system. In addition to this simulation work using AUTODYN was carried out and validated using experimental data. The experimental results indicate that hybrid steel fiber reinforced concrete panel (HSFRC) possesses excellent resistance to air blast loading as compared to normal reinforced concrete (NRC) panel. The simulation results were also found to be close with experimental data. Therefore the results have been validated using experimental data.

Isolation of Microfibrillated Cellulose (MFC) from Local Hardwood Waste, Resak (Vatica spp.)

Micrifibrillated cellulose (MFC) is generally can be prepared either by acid hydrolysis, chemical treatments, or by a high pressure refiner. In this study, the MFC of Resak’s hardwood waste with high degree of crystallinity has been obtained by an acid hydrolysis using mineral acid H2SO4. The microstructures of the MFC were characterized via X-ray diffraction (XRD) and Field emission scanning electron microscope (FESEM).

The Treated Cellulose Micro/Nano Fibers (CMNF) from Bioresources in Malaysia

Cellulose Micro/Nano fibers (CMNF) from various plants which is Resak (Vatica spp.) waste, Merbau (Intsia bijuga) waste, banana (Musa acuminata) pseudo-stem and pineapple (Ananas comosus) leaf fibers have been isolated and characterized. Isolation of microfibril cellulose from raw fibers was achieved using alkaline treatment and bleaching. The treated and untreated samples were characterized using x-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). Characterizations of treated and untreated samples were compared. The comparison between those treated and untreated samples giving different crystallite size, crystallinity, arrangement of CMNF and surface morphology from different plants. Hence, with these information different nanocomposite from CMNF can be constructed and manipulated for various application.

Hypervelocity penetration against mechanical properties of target materials

Sustainable development is growing importance issues nowadays and requires the consideration of environmental criteria to develop of all new materials and equipment. A better balance must be found in properties of oils so that the impact on the environment can be minimized. In transformers, a stable liquid, inert, with good electrical and thermal properties is necessary and the liquid must be non-toxic to environment and readily biodegradable. The objective of this research is to make a comparative study of different vegetable oils: palm oil, corn oil, rice bran oil and analyze the dielectric properties such as relative permittivity, dielectric constant and resistivity with variation temperature 30°C-90°C and breakdown voltage with different ageing time 30 days, 90 days and 180 days. The dielectric properties data of the vegetable oils are compared with the transformer oil (mineral oil) and appropriate causes for similarities and different have been discussed.Sustainable development is growing importance issues nowadays and requires the consideration of environmental criteria to develop of all new materials and equipment. A better balance must be found in properties of oils so that the impact on the environment can be minimized. In transformers, a stable liquid, inert, with good electrical and thermal properties is necessary and the liquid must be non-toxic to environment and readily biodegradable. The objective of this research is to make a comparative study of different vegetable oils: palm oil, corn oil, rice bran oil and analyze the dielectric properties such as relative permittivity, dielectric constant and resistivity with variation temperature 30°C-90°C and breakdown voltage with different ageing time 30 days, 90 days and 180 days. The dielectric properties data of the vegetable oils are compared with the transformer oil (mineral oil) and appropriate causes for similarities and different have been discussed.

Simulation and Experimental Studies on Optimum Barrel Length for High Impact Penetrator

The primary purpose of this project is about simulation and experimental studies for optimum barrel length of a high impact penetrator.This project uses the concept of two-stage light gas gun modified by using shaped charge at the first stage. Sacrificial barrel is the important part for this project. The combination of sacrificial barrel with piston serves to compress the air along the barrel at appropriate pressure. It produces sufficient amount of pressure to rupture the rupture disc and the pressure will force the projectile to travel through the barrel. There is some parameter to be investigated such as volume of air in pump barrel, strength of rupture disc and location of the piston in the sacrificial barrel. Some method is use such as calculation to determine the suitable length for the sacrificial barrel and the thickness of the rupture disc. The parameter will be use to perform simulation that will result in amount of the pressure and velocity of projectile that can be produced. The comparison result from simulation and experimental testing on the condition of sacrificial barrel and piston is obtained in this study. The significance of this project is more on the cost because this project only uses an atmospheric air as a mechanism to launch a projectile. More than that, high impact penetrator can reduce space because it is smaller compare to light gas gun.

Preliminary Study on Cutting Solid Object Using Water at Pressure Exceeding 1000 MPa

To date, the highest pump pressure available in market is 648 MPa from FLOW International Corp. Cutting with ultra high pressure reduces abrasive usage, faster cutting speed, increased depth of cuts and increase efficiency. This research explores the possibility of applying pressure exceeding 1000 MPa to push pure water to cut solid objects. 10 grams of PE4 explosives are exploded in a confined chamber with a rectangular opening. Simulations in designing the blast test jig are discussed. Simulations are done using Autodyn software. The simulation aims to get the optimum geometry that can give the highest pressure at nozzle exit. Two materials are chosen to cut; stainless steel 304 and aluminum 1100. Simulations show the optimum blast test jig can cut aluminum and stainless steel at certain thickness.

Measurement of field blast testing data using high speed data acquisition system for steel fiber reinforced concrete

This paper reports on a measurement of field blast testing data for steel fiber reinforced concrete using high speed data acquisition system. In this experiment a field blast test was conducted by the Blast Research Unit of University Pertahanan Nasional Malaysia to investigate the behavior of steel fiber reinforced concrete panel subjected to air blast loading. The steel fiber reinforced concrete panels were subjected to air blast loading using plastic explosive (PE4) weighing 1kg each at standoff distance of 0.3 meter. The parameters measured are air blast pressure, free field blast pressure and also acceleration of the slab using high speed data acquisition system and the result is presented in this paper.