Papers by Keyword: Material Design

Abstract: The paper deals with an analysis of maximal operation amplitudes of piezoelectric energy harvesting systems generating electrical energy from ambient vibrations. Energy harvesting systems could be very interesting alternative for autonomous powering of ultra-low power electronics, sensors and wireless communication. A design of piezoelectric vibration energy harvester is based on the cantilever beam design with active piezoelectric layers. The output power is proportional to an amplitude of relative oscillation of this resonance mechanism. This paper presents an analysis based on the simulation model of multidisciplinary piezoelectric energy harvesting device, enabling an optimization of its key parameters ensuring a maximal efficiency of the system. Such analysis is also essential for development of new energy harvesting systems formed of new smart materials and structures which could be integrated in future development processes.

Abstract: This paper proposes a cache replacement algorithm based on STT-MRAM magnetic memory, which aims to make the material system based on STT-MRAM magnetic memory better used. The algorithm replaces the data blocks in the cache by considering the position of the STT-MRAM magnetic memory head and the hardware characteristics of the STT-MRAM magnetic memory. This method will be different from the traditional magnetic memory-based common cache replacement algorithm. Traditional replacement algorithms are generally designed with only the algorithm to improve the cache, and the hardware characteristics of the storage device are ignored. This method can improve the material characteristics of the STT-MRAM magnetic memory by improving the cache life and efficiency.

Abstract: This paper is focused on an analysis of a multilayer ceramic-based piezoelectric vibration energy harvester, which could be excited by ambient vibrations or external forces and thus provide a useful source of electricity for modern electronics. The proposed multilayer concept of the energy harvester enables introduction of tensile / compressive residual stresses inside particular layers. These stresses are intended to be used for enhancement of the harvester ́s fracture resistance and simultaneously for the improvement of the energy gain upon its operation. A crack arrest, by means of compressive residual stresses (in the outer “non-piezo” layer), will be utilized to this end. Primarily, the extended classical laminate theory (taking into account the piezoelectric characteristics of selected layers) will be used to define various designs of particular layers with various levels of residual stresses inside them. The weight function method is subsequently employed to select a design, which is most resistant to propagation of preexisting cracks. Selected laminate configurations are verified by means of FE simulations. Such analysis is essential for development of new energy harvesting systems formed of new smart materials and structures, which could be integrated in future development processes.

Abstract: A novel high-impedance compound film material has been developed to satisfy the reservoir of many kinds of space liquid in space station. Considering the high gas-resistance and liquid-resistance, and its compatibility with the liquid in space station, the complex film was designed using 9 layers materials. The compatibility experiment and mechanical properties experiment showed that the high-impedance complex film has good compatibility with drinking water in space station. It also has excellent heat seal ability, physical and mechanical properties. The complex film also has high gas-resistance and water-resistance property, as well as great chemical corrosion-resistance property. The high-impedance complex film material offers a new method for the design and application of liquid container in space station.

Abstract: The design of the new lightweight material containing stone dust as a foaming component is described. For the composition of the material with desired properties the simplex sequential optimization was used. As an optimized value the complex point criterion was formed.The new low-cost and environmentally friendly material was designed by the help of the optimization software SOVA 1.0. The bulk density of lightweight gypsum was under 600 kg/m³ and its compressive strength was 1.1 MPa.

Abstract: Additive Manufacturing (AM) is the digital manufacturing technology by which products are fabricated directly from computer models by selectively curing, depositing or consolidating materials in successive layers. The technology has provided an opportunity to rethink the methods of product design to maximize the product performance through the synthesis of material compositions, structure, and sizes. This overview is created to relate the unique capabilities of AM technologies and discuss the methods of product design. Finally, the current problems and difficulties in this field are discussed in this paper, and this paper proposes the development direction of the product design for additive manufacturing in the future.

Abstract: This study numerically investigates the effect of creep on thermal stress states and design of ZrO₂/Ti functionally graded thermal barrier coatings (FG TBCs) based on a mean-field nonlinear micromechanical approach, which takes into account the time-independent and dependent inelastic deformation, such as plasticity of metals, creep of metals and ceramics, and diffusional mass flow at the ceramic/metal interface. The effect of creep on micro-stress states in the FG TBCs has been examined in terms of the compositional gradation patterns. The suitable compositional gradation patterns have been proposed for typical thermo-mechanical boundary conditions with different creep abilities of constitute phases in the FG TBCs.

Abstract: This paper analyzes the reasons of the defects generation of the ceramic cutting tool materials. The defects in the ceramic cutting tool materials are caused by chemical compatibility and physical mismatch during the designing process, and caused by grain abnormal growth and sintering parameters during the preparation stage. The database of low defect ceramic cutting tool is established and the data structure of the database is described. The users can use the database to design the tool material system through the mode that can reduce the defects.

Abstract: Dynamic viscosity, toughness and tenacity were used as the key indicators combined with conventional asphalt indicators such as ductility, penetration, softening point to evaluate the modification effect. The change laws of the indicators influenced by the dosages of polymer, compatilizer and stabilizer as well as the modification mechanism were analyzed; and the dosages of the three modifiers were determined. The results indicate that the modification effect is strongly influenced by the content of modifiers. Each of the modifiers plays a unique role in the performance the high viscosity asphalt. Through a particular modification technology, the optimum dosages of polymer, compatilizer and stabilizer used in self-modified high viscosity asphalt were determined at 7%, 3% and 2% respectively.

Abstract: This work proposes a rheological model for a nanoporous-elasto-hydrodynamic composite material (NPEHDCM), which can be obtained by mixing a colloid, consisted of water and water-repellent nanoporous silica micro-particles, with an adequate jellification agent. Hydrogel is modeled as a biphasic mixture consisted of a nanoporous hydrophilic isotropic and linear elastic solid matrix, and a liquid phase (water). At dynamic pressurization, water molecules exude from the hydrogel matrix and forcedly penetrate the nanopores of hydrophobic silica particles. Based on the proposed rheological model, the NPEHDCM can be suitably designed.