This paper is a case study conducted to present an approach to the process of designing
new products using virtual prototyping. During the first stage of research a digital geometric
model of the vehicle was created. Secondly it underwent a series of tests utilising the
multibody system method in order to determine the forces and displacements in selected
construction nodes of the vehicle during its movement on an uneven surface. In consequence
the most dangerous case of loads was identified. The obtained results were used to conduct
detailed strength testing of the bicycle frame and changes its geometry. For the purposes
of this case study two FEA software environments (Inventor and SolidWorks) were used. It
has been confirmed that using method allows to implement the process of creating a new
product more effectively as well as to assess the influence of the conditions of its usage more
efficiently. It was stated that using of different software environments increases the complexity
of the technical process of production preparation but at the same time increases the
certainty of prototype testing. The presented example of simulation calculations made for
the bicycle can be considered as a useful method for calculating other prototypes with high
complexity of construction due to its systematized character of chosen conditions and testing
procedure. It allows to verify the correctness of construction, functionality and perform
many analyses, which can contribute to the elimination of possible errors as early as at the
construction stage.
The techniques of micro and nano structurization of surfaces of various materials are utilized in electronics and medicine. Such procedure as wet and dry etching allows to fabricate protruded or recessed micro and nanostructures on the surface. In the paper some examples of utilization of a surface structurization, known from literature, are described. Some structurization methods and experimental results for fabrication of the arrays of sharp microtips are presented. Wet and/or dry etching, and thermal oxidation process were used to form the arrays of sharp gated and non-gated, protruded or recessed silicon microtips on silicon wafer. For the first time, the arrays of silicon carbide (SiC) microtips on glass wafer have been produced by use of the transfer mold technique. Arrays of sharp microtips are used as field electron emission cathodes for vacuum microelectronics devices. Some electron emission measurements for these cathodes have been carried out. New application of silicon microtips array in biochemistry has been tested with satisfactory results.
This paper is focusing on 3D Finite Elements Analysis (FEA) based modelling of protrusions as defects or imperfections in the XLPE high voltage cable. This study is aiming to examine the impact, protrusions have on the initiation of partial discharges. Spherical and ellipsoidal protrusions with different sizes at the conductor screen of the high voltage cable is an essential content of this paper. In addition, a spherical gas-filled void is placed inside and outside the protrusions, and a water tree produced from protrusions is under consideration. The partial discharge influence taking place at the protrusions and the stress enhancement factor is determined for all the variations mentioned to quantify the rise in the inception of partial discharges due to the protrusions.
The paper describes the recent developments of Hybrid Fibre-Reinforced Polymer (HFRP) and nano-Hybrid Fibre-Reinforced Polymer (nHFRP) bars. Hybridization of less expensive basalt fibres with carbon fibres leads to more sustainable alternative to Basalt-FRP (BFRP) bars and more economically-efficient alternative to Carbon-FRP (CFRP) bars. The New-Developed HFRP bars were subjected to tensile axial loading to investigate its structural behaviour. The effect of hybridization on tensile properties of HFRP bars was verified experimentally by comparing the results of tensile test of HFRP bars with non-hybrid BFRP bars. It is worth to mention that the difference in obtained strength characteristics between analytical and numerical considerations was very small, however the obtained results were much higher than results obtained experimentally. Authors suggested that lower results obtained experimentally can be explained by imperfect interphase development and therefore attempted to improve the chemical cohesion between constituents by adding nanosilica particles to matrix consistency.