TY  - THES
A1  - Habtemariam, Abinet Kifle
T1  - Numerical Demolition Analysis of a Slender Guyed Antenna Mast
N2  - The main purpose of the thesis is to ensure the safe demolition of old guyed antenna masts that are located in different parts of Germany. The major problem in demolition of this masts is the falling down of the masts in unexpected direction because of buckling problem. The objective of this thesis is development of a numerical models using finite element method (FEM) and assuring a controlled collapse by coming up with different time setups for the detonation of explosives which are responsible for cutting down the cables. The result of this thesis will avoid unexpected outcomes during the demolition processes and prevent risk of collapsing of the mast over near by structures.
KW  - Abbruch
KW  - Finite-Elemente-Methode
KW  - Optimierung
KW  - Demolition
KW  - Guyed antenna masts
KW  - Explicit finite element method
KW  - Optimization
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210723-44609
ER  - 
TY  - JOUR
A1  - Ataollahi Oshkour, Azim
A1  - Talebi, Hossein
A1  - Seyed Shirazi, Seyed Farid
A1  - Bayat, Mehdi
A1  - Yau, Yat Huang
A1  - Tarlochan, Faris
A1  - Abu Osman, Noor Azuan
T1  - Comparison of various functionally graded femoral prostheses by finite element analysis
JF  - Scientific World Journal
N2  - This study is focused on finite element analysis of a model comprising femur into which a femoral component of a total hip replacement was implanted. The considered prosthesis is fabricated from a functionally graded material (FGM) comprising a layer of a titanium alloy bonded to a layer of hydroxyapatite. The elastic modulus of the FGM was adjusted in the radial, longitudinal, and longitudinal-radial directions by altering the volume fraction gradient exponent. Four cases were studied, involving two different methods of anchoring the prosthesis to the spongy bone and two cases of applied loading. The results revealed that the FG prostheses provoked more SED to the bone. The FG prostheses carried less stress, while more stress was induced to the bone and cement. Meanwhile, less shear interface stress was stimulated to the prosthesis-bone interface in the noncemented FG prostheses. The cement-bone interface carried more stress compared to the prosthesis-cement interface. Stair climbing induced more harmful effects to the implanted femur components compared to the normal walking by causing more stress. Therefore, stress shielding, developed stresses, and interface stresses in the THR components could be adjusted through the controlling stiffness of the FG prosthesis by managing volume fraction gradient exponent.
KW  - Finite-Elemente-Methode
KW  - Hüftgelenk
KW  - Funktioneller Gradientenwerkstoff
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170413-31194
ER  -