Papers by Keyword: Material Optimization

Abstract: The building industry offers a wide range of materials which can be used for the production of various structural elements. Fibre reinforced concrete (FRC) is a material which is more frequently utilized for concrete structures. The reason is its physical and mechanical properties which contribute to traditional concrete elements and structures various economical benefits such as structure subtlety, part or full elimination of conventional reinforcement, resistance to mechanical loading and surrounding environment. Therefore, it is necessary to search for appropriate structures where the benefits of FRC could be used. First of all it is necessary to seek for structures which owing to their geometry and intended use seem to be appropriate for FRC application. It can be either new structural elements or existing structural elements made of a different material. During a material optimization there are many parameters to take into account which include production costs, manufacturing technology, structural behaviour, ultimate bearing capacity and durability of proposed member. The efficiency of material optimization is determined by comparing these parameters. While it is relatively easy and cost efficient to determine and evaluate the production costs, structure durability and manufacturing technology, to describe the structural behaviour of innovative elements is a complex task. However there are many sophisticated software which are capable to accurately simulate the behaviour of structural elements by using modern computational methods. At the end of feasibility study, experimental testing is conducted on full-scale pilot elements with the aim to verify their real behaviour as well as to optimize the computational model. As a result, many innovative FRC based structural elements have been developed at Czech Technical University in Prague in cooperation with construction companies.

Abstract: The growing demand for advanced manufacturing processes calls for reduction in manufacturing cost and manufacturing time. Fused Deposition Modelling (FDM) is one of the rapidly developing rapid Prototyping (RP) process. In this work an effort has made to make FDM process cost effective by replacing solid model with shelled model in-filled with user-defined parametric cellular structures. This approach helps in keeping a balance between material usages, build time and mechanical properties. The proposed method is implemented on a few specimens and results signify that 20-30% expensive build material as well as build time can be saved by this approach. The whole algorithm is based on .STL format, and is coded in MATLAB providing a versatile and widely acceptable platform.

Abstract: According to the factor of the characteristics of the wall material, wall pressure, as well as the influence of the wall material, the article aims at the alternative wall material in view of the unobvious functional difference, and builds wall material evaluation system. Then based on the theory of gray system, the present article conducts a comprehensive quantitative and qualitative analysis by analytic hierarchy process, and optimize the best wall material so as to provide a certain reference for the designing and construction side in the optimization of wall material.

Abstract: In recent years the wind turbine blade has been the subject of comprehensive study and research amongst all other components of the wind turbine. As our appetite for renewable energy from the wind turbine continues to increase, companies now focus on rotor blades which can go up to 80m in length. The blade material not only have to face large aerodynamic, inertial and fatigue loads but are now being designed to endure environmental effects such as Ultraviolet degradation of surface, accumulation of dust particles at sandy locations, ice accretion on blades in cold countries, insect collision on blades and moisture ingress. All this is considered to ensure that the blades complete its designated life span. Furthermore exponential increase in composite blade manufacturing is causing a substantial amount of unrecyclable material. All these issues raise challenges for wind blade material use, its capacity to solve above mentioned problems and also maintain its structural integrity. This paper takes on this challenge by optimizing from the properties, merits, demerits and cost of different possible competing materials. Then the material is checked for its structural integrity through Finite Element Analysis simulation using standards like IEC-61400-1.This paper also shows the future direction of research by elaborating the influence nanotechnology can have in the improvement of the wind blade.

Abstract: The genetic algorithm method was used in the present work as an alternative to classical calculation methods. It can be used in the situations where we search an optimal solution and a problem has many variable parameters. In this work the genetic algorithm method was applied in order to decompose the texture function into ideal components and also to optimize elastic constants by an appropriate choice of texture function. These example applications of genetic algorithm method show its potential in the field of material engineering.

Abstract: In this paper, regardless of the cooling system of the mold, the optimization design for the material distribution of heterogeneous injection mold is investigated, which is made of two base materials with different thermo-mechanical properties. A mathematical model is constructed in which both a function related to casting average temperature and the temperature gradients throughout all the cavities during the solidification process are taken as the objective function while the von Mises stress constraints of the mold are considered for reducing the stress concentration in the mold. The Finite element method (FEM) and the finite difference method (FDM) are utilized to analyze the transient heat conduction of the mold and casting. The constrained optimal design problem is solved using real coded genetic algorithm. A smooth bicubic B-spline interpolation is proposed for representing the continuous variation of material distribution. The effectiveness of the optimization results is verified by a numerical example.