15 research outputs found
Implications of serial measurements of natriuretic peptides in heart failure: insights from BIOSTAT‐CHF
No abstract available
Electric Car Chassis for Shell Eco Marathon Competition: Design, Modelling and Finite Element Analysis
The increasing demand for energy efficient electric cars, in the automotive sector, entails the need for improvement of their structures, especially the chassis, because of its multifaceted role on the vehicle dynamic behaviour. The major criteria for the development of electric car chassis are the stiffness and strength enhancement subject to mass reduction as well as cost and time elimination. Towards this direction, this work indicates an integrated methodology of developing an electric car chassis considering the modeling and simulation concurrently. The chassis has been designed in compliance with the regulations of Shell Eco Marathon competition. This methodology is implemented both by the use of our chassis load calculator (CLC) model, which automatically calculates the total loads applied on the vehicle’s chassis and by the determination of a worst case stress scenario. Under this extreme stress scenario, the model’s output was evaluated for the chassis design and the FEA method was performed by the pre-processor ANSA and the solver Ansys. This method could be characterized as an accurate ultrafast and cost-efficient method
Optimised ultrafast lightweight design and finite element modelling of a CFRP monocoque electric car chassis
ScienceDirect Agricultural use of microfiltered olive mill wastewater: effects on maize production and soil properties
Abstract The disposal of olive mill wastewater (OMWW) is considered as one of the most serious environmental problems in the Mediterranean region. This study constitutes part of a holistic OMWW management approach aiming at the production of high added value products from OMWW with zero discharge. OMWW constitutes an organic material that could be recycled back to the soil after its treatment with microfiltration, and used as liquid fertilizer for plant production, thus leading to an environmentally friendly cultivation method with minor carbon footprint, since wastewater would (partially or fully) substitute mineral fertilizers, fresh water savings, and also economic benefits to the farmer. Microfiltered OMWW (MF-OMWW) was applied to maize cultivation in a clay loam soil using two rates of 25 and 50 Mg ha -1 , with the addition of mineral fertilization of 200 kg N ha -1 . Furthermore, a treatment of only MF-OMWW applied at the rates of 50 Mg ha -1 and an only mineral fertilization treatment were used. The four treatments were replicated four times. The results of the 1 st year experiment showed that the different amounts of MF-OMWW used had no significant effect on soil properties. Maize yield, kernel moisture and fat content were not significantly influenced by the different treatments, whereas kernel protein, starch, fiber and ash content were significantly affected. Considering all quality and quantity parameters studied, the treatment with only mineral fertilizer N application gave similar results with the only MF-OMWW treatment, indicating the potential of mineral fertilizer full substitution by MF-OMWW, under the conditions of our study
Lightweight Design and Welding Manufacturing of a Hydrogen Fuel Cell Powered Car’s Chassis
The development of the chassis for the hydrogen fuel cell powered car has been involved in the designing and manufacturing aspects, while taking into consideration the mass, strength, stiffness, centre of gravity (COG), and manufacturing cost requirements. Towards this direction, a chassis design is proposed employing a space frame structure and constructed by an aluminium alloy with great strength. The structural design has been derived through the lightweight engineering approaches in conjunction with the part consolidation, Design for Assembly (DFA) and Design for Manufacture methods. Moreover, it has been performed in compliance with the safety regulations of the Shell Eco Marathon racing competition. The material’s principal characteristics are the great strength, the low mass, as well as the great workability, machinability, and weldability. Following the national and global environmental issues, the recyclable characteristics of the aluminium alloy are an extra asset. Furthermore, the existence of aluminium alloy manufacturers around the fabricating area provides low cost supply and fast delivery benefits. The integration of the fuel cell powered vehicle is obtained through the designing and the manufacturing processes of the chassis and the parts fitted on the chassis. The manufacturing procedures are described thoroughly; mainly consisting of the cutting and welding processes and the assembling of the parts that are fitted on the chassis. Additionally, the proper welding parameters for the custom chassis design are investigated and are selected after deductive reasoning. The quality control of the weld joints is conducted by non-destructive methods (NDT) ensuring the required structural properties of the welds. A combination of the selected material, the specific type of the chassis, and the manufacturing processes lead to construction simplicity in a low manufacturing cost by using the existing laboratory equipment. Furthermore, the designing and manufacturing parameters lead to a stiff with a low centre of gravity, and the most lightweight chassis of the urban concept category at the Shell Eco Marathon race
Optimised ultrafast lightweight design and finite element modelling of a CFRP monocoque electric car chassis
Summarization: A breakthrough in the process method has been developed by combined considerations in the demands of "Shell Eco Marathon" using finite element modelling (FEM). Ultrafast calculations have revealed novel chassis development. The most critical factors in designing the new chassis are the reduction of the weight, the improvement of strength and stiffness, the reduction of material and the manufacturing cost. The simple structural surfaces (SSS) method was used for an electric car so as the type of loading conditions which are applied to the chassis structure to be predicted. Afterwards, a new design approach for a lightweight carbon-fibre reinforced polymer (CFRP) monocoque chassis is proposed which conforms to structural, ergonomic, safety and aesthetic requirements. The SSS method in conjunction with the creation of the chassis load calculator (CLC) model and both the specialised and integrated methodology of the processing procedure through FEM, have attained the overcoming of the time consuming conceptual design process.Παρουσιάστηκε στο: International Journal of Electric and Hybrid Vehicle