Papers by Keyword: Form Factor

Abstract: The article substantiates the main possibilities of filling with irregular bodies, and provides a visual analysis of the parameters formed as a result of structures. It was found out that the form factor acts as the main indicator of the characteristic parameter of changes in the structure and all other parameters of an inhomogeneous medium. It was also found out that when filling a container with irregular ellipsoid elements, the conditions for non-opening (one-way contact) must be met. The obtained calculations of the form factor show the minimum value of the average coordination number of an inhomogeneous medium. This allows us to assert and predict reliable modelling results (± 2-3%). It is also important that the developed simulation model for modelling an inhomogeneous medium using an irregular (ellipsoid) shape of elements can significantly reduce the time spent on conducting field experiments, as well as simulate irregular elements with different shape factors.

Abstract: This study shows that a thin Ni film on Al/Ti/4H-SiC metal pads allows to preserve the pad form factor during a 1000 °C/2 min treatment, provided that the Al and Ti film thicknesses are sufficiently thin. Moreover, by reducing the Al to Ti thickness ratio, droplet formation in the contact area is avoided and a mirror-like appearance is obtained. This optimal contact morphology corresponds to a specific contact resistance of few 10^-4 Ωcm² at room temperature on p-type 4H-SiC with resistivity in the range 0.1 – 1 Ωcm.

Abstract: The mechanism for the change in the size of the geometry of graphite crystallites in polyacrylonitrile-based carbon fibers heat treated at 1500–2500 °C is proposed. The study indicated that the growth transition temperature of graphite crystallites in carbon fibers is 2000 °C. Above 2000 °C, the interlayer space (d₀₀₂) decreases slowly and an ordered graphitic structure forms. Below 2000 °C, the variation in the size of the crystallites along the directions of the axis (L_a‖) and the radius (L_a⊥) of the carbon fibers that were heat treated at various temperatures was almost the same and the crystallite form factor, L_a‖/L_a⊥, which is nearly 1. Above 2000 °C, L_a‖/L_a⊥ increases rapidly because the anisotropy of the arrangements of the crystallites in the carbon fibers and the geometry of the crystallites change from being square to becoming rectangular. The crystallite thickness (L_c) also increases with an increasing temperature and below 2000 °C the crystallite form factor (L_a‖/L_c) increases rapidly. Above 2000 °C, the L_a‖/L_c stabilized at 3.1. The different growth models in the different directions are the intrinsic root for the variations in the crystallite geometries that underwent high-temperature heat treatments.

Abstract: In this paper, taking a 7000 TEU container ship as an example, research on optimization design of mold lines of bulbous bow for container ships is carried out. Firstly, geometric parameters of bulbous bow are selected to be as variables to construct 7 computing molds, then CFD methods are employed to calculate ship resistance and parameters of wave field generated by ship moving, as well as Michell integration is used to determine the coefficient of wave-making resistance. Minimization of resistance is taken as the aim function to obtain the optimum geometric parameters of mold lines at bow. The results of mold testing express that the mold lines of bulbous bow for container vessel optimized by above methods are credible and valuable for engineering practice.

Abstract: Electronic information products based on ergonomics, on the basis of the research in the form in human research and design. From the electronic information products shape colour, modelling, material texture and interface aspects are studied, that "People-Oriented" design idea was fully manifested in person to use electronic devices, functional principle in operating mode, physiological, psychological, product semantics of human concern gives products, electronic equipment, more comfortable and pleasant that the external form of electronic information equipment development direction.

Abstract: The form factor of abrasion particles is one of the most important Influencing factors of abrasion resistance of concrete. In order to evaluate the serves life of concrete, a relationship about the form factor of abrasion particles and the wear degree of abrasion resistance of concrete should be established. In this paper, wear process of basalt on concrete was studied under the flow velocity form 1.7m/s to2.4m/s by a improved under water method test equipment. Meanwhile, an image acquisition method was used to get the form factor of basalt to measure the influence of form factor of basalt on wear degree of concrete. The result shows: the abrasion rate of concrete is higher when the flow velocity is faster and the particle form is sharper, and there is an exponential function relationship between particle forms and abrasion rate.

Abstract: As a new construction material, fiber reinforced polymeric plastic structural shapes are readily available. Therefore, new construction and existing structure rehabilitation using FRP materials are ever increasing trend because of FRP material’s chemical and mechanical properties compared with those of conventional construction materials such as steel and concrete. Among the structural composites, pultruded fiber reinforced polymeric plastic structural members are the most popular for the civil engineering applications because of the cost effectiveness. However, they are made of fiber reinforced polymer resin system, they have relatively low modulus of elasticity and also cross-sections of structural shapes are composed of thin plate components such as flange and web. Therefore, structural stability is an important issue in the design of pultruded structural members. For the design of pultruded structural member under compression, buckling and post-buckling strengths of plate components may be taken into account. In the structural steel design following AISC/LRFD, in addition to the buckling strength, the nonuniform stress distribution in the section is incorporated with a form factor. In this paper, the form factor for the design of pultruded structural member under compression is investigated by experiment. Based on the experimental results, the form factor for the design of pultruded structural shapes have been suggested.

Abstract: As a new construction material, fiber reinforced polymeric plastic structural shapes are readily available. Therefore, construction and structure rehabilitation using FRP materials are an ever increasing trend because of FRP material’s superior chemical and mechanical properties compared with those of conventional construction materials such as steel and concrete. Among the FRP materials, pultruded fiber reinforced polymeric plastics are the most popular for civil engineering applications. However, it has relatively low modulus of elasticity and also cross-section of structural shapes is composed of plate components such as flange and web. Therefore, stability is an important issue in the design of pultruded structural shapes. For the design of pultruded structural member under compression, buckling and post-buckling strengths of plate components should be taken into account. In the structural steel design following AISC/ LRFD, this effect, in addition to the buckling strength, is incorporated with a form factor. In this research, the form factor for the design of pultruded structural shapes under compression is investigated. Based on the analytical study, the form factor for the design of pultruded structural shapes have been suggested.