An Hp-Adaptive Finite Element Procedure For Fluid-Structure Interaction In Fully Eulerian Framework

This thesis attempts to implement a fully automatic hp-adaptive finite element procedure for fluid-structure interaction (FSI) problems in two dimensions. This work hypotesizes the efficacy of Fully Eulerian framework of FSI in hp-adaptivity on an a posteriori error estimator and adaptation for minimization of error in energy norm. Automatic mesh adaptation over triangular elements is handled by red-green-blue (RGB) refinement method. An effective mesh adaptivity to avoid excessive growth of unknowns is also addressed. Since the hp-method uses high order polynomials as approximation functions, the resulting system matrices are less sparse leading to the notion of FSI computation with parallelism. The parallel hp-adaptive computation is assessed with the conventional uniform and h refinement on a number of benchmark test cases. Subsequently, the efficacy of the fully Eulerian framework is compared to the well known Arbitrary Lagrangian Framework( ALE) for two different material models, namely, the St. Venant Kirchoff and the Neo-Hookean models. It was found that the fully Eulerian framework provides accurate FSI predictions for large deformation without need of frequent remeshing. The hp-adaptive method was also found to be a viable approach in obtaining accurate solutions without much compromise in computer memory and time. Furthermore, the integration of parallelism is successful in reducing the computation time by up to two orders of magnitude relative to the serial solver. For the comparisons between the ALE and the fully Eulerian frameworks, the computed solutions in all test cases are observed to be in agreement with each other

Structural Assessment of Lead Free Solder Joint of Miniaturized Electronics Assembly

This paper presents a study on structural assessment of ultra-fine package assembly with nano-composites lead free solder joint after reflow soldering process. In this work, various nanoparticles (i.e. TiO2, Fe2O3 and NiO) with different weightage percentage (i.e., 0.01, 0.05 and 0.15 wt.%) were successfully incorporated into SAC305 solder paste using the mechanical solder paste mixer to synthesize novel lead-free composite solders. Effects of the nanoparticles addition on the quality of joining and fillet height between various weightage (wt.%) for the ultra-fine package assembly in the reflow soldering process have been investigated after the reflow soldering process by using the scanning electron microscope (SEM) system equipped with an energy dispersive X-ray spectroscopy (EDS) and XTV 160 x-ray inspection system. The experimental results show the increment of TiO2, Fe2O3 and NiO nanoparticles addition to 0.15wt.%, 0.05wt.% and 0.01wt.%, respectively, produce highest fillet height of each composition of nanoparticles solder paste. Among all these new composition of nanoparticles solder paste, NiO nanoparticles reinforced solder paste with 0.01wt.% yielded highest fillet height The miniaturized solder joints do not cause any problem in terms of solder voids. The findings show the capability of the reflow soldering process in assembling miniaturized electronics assembly and expected to provide a reference in electronic package industry

Prediction of the Flow-Induced Vibration Response of the Chenderoh Dam Left Bank Section

Flow-induced vibration is a common phenomenon that happened in any of dam structures during the operational condition. This includes the effect of water spilling from the upstream to the downstream of the dam due to high water volume at the upstream side. the release of water from the dam can be beneficial in generating the electricity source to the surrounding areas. However, in some cases, the spill of water can induced the significant vibration effects to the dam structure. In this study, the prediction of the flow-induced vibration response at the left bank section of the real scale Malaysian Chenderoh Dam model is simulated using the ANSYS software. the input force disturbances from the flow of the water at the left bank section during the normal water spilling condition is investigated. the results of frequency domain response and operational defection shapes (ODS) from the effect of flow-induced vibration are compared with the natural frequencies and mode shapes of the dam. From the results, the transient vibration responses due to the flow of water happened at the frequency of 13.3 Hz while the natural frequency of the left bank section occurred at 52.3 Hz, which indicates that there is no resonance phenomenon for the normal case of water spilling at the left bank section of the dam structure. This result is useful for the dam operation section in order to avoid any disaster of the dam structure

Calculating the Moduli Elasticity For Reinforced Concrete Using New Rule of Mixtures Approach for the Dam Structure

Dam is the important structure use for water domestic store, electricity power supply, irrigation and flood control. Dam deal with reinforced concrete as a main material in construction. the material considerable safe when ability to support external and internal load. the capability of dam material due to safety is effect by degradation. Prevention monitoring must be conducted for high risk structure. Thus, moduli elastic is a mechanical property to measure stiffness and had relationship between stress and strain of material. While non-destructive and destructive testing in site inspection does not include reinforce and give incorrect moduli elasticity. New approach rule of mixture (Rom) with solid work software refer to United States Department of the Interior Bureau of Reclamation (USBR) standard design for small dam, give reliability monitoring with true sustain modulus elasticity of dam structure time by time. the concrete properties for sustain of moduli elasticity standard type gravity concrete dam value is 20.684 GPa. If the value decreases drastically from the standard, high precaution must be taken

Structural Dynamic Analysis of the Chenderoh Dam Sector Gate Section

The dynamic characteristics such as natural frequencies, mode shapes and frequency response function (FRF) are the important characteristics to be investigated to access the level of durability of any dam structures. These characteristics are important since it will be the reference information for any operational methods to be used for the dam structures. In this study, one of the real dam (i.e., Chenderoh Dam) that available in Malaysia is taken into consideration, where the dynamic analysis of the sector gate section of the dam structure is investigated. the real scale of the sector gate section is measured on site and modelled into the CAD software with the consideration of real build-in materials. Then, the finite element (FE) model is constructed in ANSYS software with the required boundary condition and meshing sensitivity analysis. From the result of modal analysis, 30 natural frequencies are determined in the range of 0.5904 Hz to 8.471 Hz together with the mode shapes but only the most significant natural frequencies will be shown in this paper. In addition, all three axes of the FRF graphs show an agreement for the highest natural frequency value at 7.95 Hz, where the maximum deflection occurred in x axis direction with 2.03 × 10-7 m

An assessment of the Edu-Tourism @UKMlivinglab Package test-run

An edu-tourism package has been developed which encompassed nature-based tourism at the natural living laboratories of Universiti Kebangsaan Malaysia (UKM). With the theme “From Mountain to the Reef”, this package comprised of tourism module based on the natural ecosystem of respective living laboratory of UKM, involving four natural habitats; highland, lowland, freshwater and marine. In order to assess the effectiveness of the module, we have distributed a set of questionnaire to the participants during the test-run, involving all the living lab facilities. This pilot study involved 13 participants from various academic background, enrolling either as undergraduates or postgraduates study at UKM. The result of the questionnaire showed positive feedbacks from the participants for both the learning modules, as well as the overall program. There were however, several room of improvements to be made from the feedbacks. This package is expected to be marketed locally and internationally for students and public, in order to generate revenue for the university and stakeholders. This project has proven to be research translated to the community through the empowering of the human capitals (staffs and local community) through the living laboratory facilities