Vol. 15 No. 2 (2000)

Metode finite element alternating (FEAM) merupakan salah satu metode untuk menentukan faktor intensitas tegangan pada kasus retak berganda. Metode ini merupakan gabungan dari metode finite element dan solusi analitis untuk kasus retak pada pelat dengan lebar tak berhingga, Penelitian yang dilakukan merupakan penelitian lanjutan yang diterapkan untuk kasus khusus yaitu sambungan susun (lap-joint) yang merupakan salah satu sambungan penting pada struktur pesawat terbang. Untuk itu pada penelitian ini metode finite element alternating dikembangkan untuk geometri pelat berlubang. Penelitian…

Technology development advances in recent years produce materials having higher strength, complicated shape and high accuracy. These have placed demands on the new technology in machining processes. Non-conventional machining processes are providing effective solutions to the problem mentioned above.Wire EDM machining is one of some non-conventional machining processes which is using wire as tool. The limitation of this technique as also happened with other non-conventional machining processes is a lower rate of material removal comparing to the conventional processes.This study was conducted…

Single crystal direction can be determined by x-ray diffraction. The determination of this crystal direction can also be carried out by using ultrasonic method. In this method the ultrasonic wave velocity propagating through the crystal is measured. From this velocity measurement then the crystal direction can be determined. This paper deals with the results of a research about the direction determination of cubic single crystal using ultrasonic wave. There are two methods used, namely graphical method and computer method. These two methods used the same data, i.e. velocity data for all…

This paper presents the stress intensity factor (SIF) analysis for unidirectional fiber-matrix lamina containing center crack under uniaxial loading. Several variables are considered on the influence to the stress intensification factor i.e. fiber direction,θ, crack dimension parameter, 2a/L, fiber and matrix volume fraction, Vf, Vm, fiber and matrix stiffness ration, Ef/Em, and lamina thickness. The stress-strain equations for the lamina are derived using micromechanic approach. The governing equations are solved numerically using the finite element method with triangular type…