Rakhmad Arief Siregar, Dr.http://dspace.unimap.edu.my:80/xmlui/handle/123456789/330172024-03-27T18:27:45Z2024-03-27T18:27:45ZStress concentration factors of various adjacent holes configurations in a spherical pressure vesselKhairul, FuadRakhmad Arief, Siregar, Dr.Rangkuti, Ch.Ariwahjoedi, B.M, Firdaushttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/351892014-06-08T12:51:24Z2007-12-01T00:00:00ZStress concentration factors of various adjacent holes configurations in a spherical pressure vessel
Khairul, Fuad; Rakhmad Arief, Siregar, Dr.; Rangkuti, Ch.; Ariwahjoedi, B.; M, Firdaus
The analysis of stress concentration factor (SCF) of adjacent holes in a spherical pressure vessel can be approached by considering a thin plate undergoing hydrostatic stresses. This work adopts the approach to investigate the SCF of various adjacent holes configurations in a spherical pressure vessel using finite element analysis. The von Mises stress is considered to determine the SCF. Various arrangements of adjacent holes are investigated i.e., two, three, four, and five adjacent holes are taken into account. The SCF curves with respect to the ratio of the distance between adjacent holes to the diameter of hole, L/d, and for a certain ratio of the diameter of hole to the plate thickness, d/t, are then plotted. The results show that the decreasing of L/d will affect the increasing of SCF, while for the case of five adjacent holes configuration, the increasing of d/t doesn’t make any significant effect to the increasing of SCF.
Proceedings of the 5th Australasian Congress on Applied Mechanics (ACAM) 2007 at Brisbane, Australia on 10 December 2007 through 12 December 2007. Link to publisher's homepage at http://www.engineersaustralia.org.au/
2007-12-01T00:00:00ZPartial discharge measurement and vibration monitoring on power transformer case study on power transformer with high level noise (75.22 dB)Solin, I. K.Yolanda, O.Rakhmad Arief, Siregar, Dr.http://dspace.unimap.edu.my:80/xmlui/handle/123456789/351882014-06-08T07:00:27Z2009-07-01T00:00:00ZPartial discharge measurement and vibration monitoring on power transformer case study on power transformer with high level noise (75.22 dB)
Solin, I. K.; Yolanda, O.; Rakhmad Arief, Siregar, Dr.
This paper is a study and share information of partial discharge measurement and vibration monitoring on power transformer. Power transformer is one of the critical components in power plant and transmission power system. Therefore, an appropriate maintenance program should be applied to the transformer in order to make power system more reliable and to prevent transformer failure at early stage. One of the problems concerning the power transformer is high level noise during its operation.
Proceedings of the 9th International Conference on the Properties and Applications of Dielectric Materials (ICPADM) 2009 at Harbin, China on 19 July 2009 through 23 July 2009. Link to publisher's homepage at http://ezproxy.unimap.edu.my:2080/Xplore/dynhome.jsp?tag=1
2009-07-01T00:00:00ZDynamic splitting-tensile test and numerical analysis for brittle materialsRakhmad Arief, Siregar, Dr.Daimaruya, MasashiKhairul, Fuadhttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/351862014-06-07T23:16:31Z2007-01-01T00:00:00ZDynamic splitting-tensile test and numerical analysis for brittle materials
Rakhmad Arief, Siregar, Dr.; Daimaruya, Masashi; Khairul, Fuad
This paper is concerned with the dynamic splitting-tensile test for brittle materials. An experiment on the dynamic splitting-tension has been performed on cylindrical concrete specimens by utilizing a Split Hopkinson Pressure Bar. To observe the stress distribution and detect the crack initiation, some specimens were instrumented with strain and crack gages. A numerical analysis was conducted, using LS-DYNA code, to verify the experimental data. The results of the stress distribution in the dynamic condition, with respect to the time, were almost identical to those in the static condition. The numerical analysis identifies the initial crack and generates the crack pattern on the concrete material. In addition, the result of the strain-rate sensitivity of concrete materials is presented.
Proceeding of The 2nd International Conference on Solid State Science and Technology (ICSSST) 2006 at Kuala Terengganu, Malaysia on 4 September 2006 through 6 September 2006. Link to publisher's homepage at http://proceedings.aip.org/
2007-01-01T00:00:00ZEffect of blockage size on pipe vibrationNur Liyana, Tajul LileRakhmad Arief, SiregarM.J., HasnulJ.C., Leonghttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/321282014-02-24T06:43:33Z2012-12-01T00:00:00ZEffect of blockage size on pipe vibration
Nur Liyana, Tajul Lile; Rakhmad Arief, Siregar; M.J., Hasnul; J.C., Leong
Circular pipes are widely used to convey goods to a desired location. Flow inside a pipe needs to be smoothed and unobstructed to ensure an optimize flow of particle. However, pipes are prone to clogging or blocking due to deposition of unwanted impurities and external objects. Built up inside a circular pipe will affect the flow velocity and pressure within the pipe. This paper presents a method of assessing blockage inside a pipe by using vibration analysis. The effect of blockage was observed through changes in pipe vibration response and also turbulence intensity. The changes in vibration parameters were identified together with the reduction of flow area due to increasing blockage size.
Link to publisher's homepage at http://www.scientific.net
2012-12-01T00:00:00Z