J. Holzweber, Z. Major
The fatigue behavior of different thermoplastic polyurethanes is discussed and compared to a cross-linked thermoset H-NBR elastomer. The characterization of the fatigue behavior is of great interest for long-term properties under cyclic loading. There is hardly any fatigue data available for these new classes of materials. There are two common ways to describe the lifetime of an elastomer fatigue behavior. One method is the classic fatigue test to generate the Wöhler curve. The other approach is focused on fatigue crack growth using the Tearing Energy or J-Integral concept. Displacement...
TC15 Youth Symposium 2014
· TC15
· 2014
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D. Gubencu, C. Sosdean, E. Szücs
Actual global challenges, like the depletion of conventional resources and global warming forced the society to adopt sustainable development policies, which implies achieving growth without compromising the chances of next generations. Among the objectives of sustainable development, one of the most important is referring to the limitation of climate changes and its negative effects on environment and society, by implementing green energy solutions. Wind energy is one of the renewable energy powers which accomplished a rapid growth during the last decade. Consequently, promoting and...
TC15 Youth Symposium 2014
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· 2014
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N. Golinelli, A. Spaggiari
In the present study the dynamic behavior of a commercial silicon based magnetorheological elastomer was investigated. This material presents a non-newtonian characteristics whose response depends on the rate at which it is stressed. The damping properties under dynamic load of these materials have been studied in technical literature, while the influence of the magnetic field on the dynamic shear modulus is unknown. Hence, the aim of this paper is to test the change in dynamic shear modulus under a sinusoidal strain with amplitude of 2 and 4 mm, cyclic frequency of 4, 8 and 12 Hz and...
TC15 Youth Symposium 2014
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· 2014
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T. Fila, P. Zlámal, D. Kytýr, P. Koudelka, T. Doktor, O. Jirousek
In this paper, compact loading device for micro-CT measurements under applied load was used in a series of instrumented compressive test of bone sample. Tested bone samples were loaded in several deformation steps and micro-CT scanning was carried out in each step. Reconstructed three-dimensional data of intact bone sample were used to develop 3D model of the specimen. Data from each deformation step were processed by DVC method for identification of displacement and strain fields and thus for evaluation of deformation response of human trabecular bone sample.
TC15 Youth Symposium 2014
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· 2014
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K. Fellner, P. F. Fuchs, G. Pinter
The “Single Via Thermal Cycle Test” (SVTCT) is a thermal cycle test used for life time assessment of Printed Circuit Boards (PCBs) under cyclic thermal loads. During the SVTCT, the electrical conductivities of the interconnections (vias) of the tested PCB are monitored by resistance measurements. Hence, by a decrease of electrical conductivity, failure can be detected. A single via in a PCB is modeled using an axisymmetric simulation model. The simulations are conducted decoupled. One model for computing the temperature field in the PCB and another model to compute the stress and strain...
TC15 Youth Symposium 2014
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· 2014
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R. da S. Correa, F. T. Stumpf
Throughout the extent of its life, a mooring line used in an offshore oil platform working in deep and ultra-deepwater is subjected to the environmental conditions present at seabed. Along with low water temperature, high salinity, and acidity, the materials capacity of absorbing water plays an important role when it comes to its mechanical behavior in service conditions. Previous studies have shown that the longer a synthetic rope is in contact with seawater, both its force-elongation behavior and its ultimate strength are affected. The phenomenon of the materials water absorption is known...
TC15 Youth Symposium 2014
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· 2014
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F. M. Clain, O. C. Nogueira
Mooring ropes used in offshore oil platforms are exposed to a set of environmental conditions that can be crucial to their behavior in service. When one is talking of synthetic fiber ropes, such as Nylon, PET or HMPE, for instance, of all these peculiar conditions, the water temperature at the seabed can be pointed out as the one that affects the ropes mechanical response the most. For this specific reason, sometimes there can be a significant discrepancy between data collected at room temperature during tensile test in these components and their actual behavior in service. Seeking to...
TC15 Youth Symposium 2014
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· 2014
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C. Casavola, A. Cazzato, V. Moramarco
Friction Stir Welding (FSW), developed at The Welding Institute (TWI) in 1991, is a new solid-state welding process. In this technique, the material does not reach the fusion but the joint is the consequence of the plasticization resulting from the generation of heat by friction and the stirring action of the pin on the material due to the rotation and the displacement of a non-consumable tool. Thus, the FSW reaches temperatures lower than those reached by conventional fusion welds. Laser Assisted Friction Stir Welding (LAFSW) is a combined welding technique in which the FSW is assisted,...
TC15 Youth Symposium 2014
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· 2014
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C. Barile, C. Casavola, G. Pappalettera, C. Pappalettere
Hole drilling is the most widespread method for measuring residual stress. This method is based on the principle that drilling a hole in a material causes stress relaxation; by measuring the resulting strain it is possible to calculate the initial residual stress. Recently optical systems were introduced to replace strain gage rosette since they can provide full field measurements with high sensitivity. When using ESPI technique, the analysis area, that is to say, the portion of the image which must be used for measuring strain is defined by the operator. Proper choice of this area can be...
TC15 Youth Symposium 2014
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· 2014
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M. Bajgrowicz
Artificial valve replacement is a common procedure in case of heart valve disorders treatment. The main task of this prosthesis is to generate blood flow similar to flow generated by natural, human valve. Velocity distribution depends mainly on the geometry of the valve. That is why it should be analysed and modified in case to obtain the best results. The objective of this study was to numerically investigate how geometry of valve (the maximal opening angle) influences velocity distribution behind a valve in terms of potential negative effect on blood components. For this purpose seven 2D...
TC15 Youth Symposium 2014
· TC15
· 2014
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