An automotive engine cradle supports many crucial components and systems, such as an engine, transmission, and suspension. Important performance measures for the design of an engine cradle include ...stiffness, natural frequency, and durability, while minimizing weight is of primary concern. This paper presents an effective and efficient methodology for engine cradle design from conceptual design to detailed design using design optimization. First, topology optimization was applied on a solid model which only contains the possible engine cradle design space, and an optimum conceptual design was determined which minimizes weight while satisfying all stiffness constraints. Based on topology optimization results, a design review was conducted, and a revised model was created which addresses all structural and manufacturability concerns. Shape and size optimization was then performed in the detailed design stage to further minimize the mass while meeting the stiffness and natural frequency targets. Lastly, the final design was validated for durability. The initial design domain had the mass of 82.6 kg; topology optimization in conceptual design reduced the mass to 26.7 kg; and the detailed design task involving shape and size optimization further reduced the mass to 21.4 kg.
A high recovery of lithium from recycled lithium ion batteries (LIBs) is essential to ensure the growth and sustainability of the electrical vehicle market. Without recycling, lithium demand is ...predicted to outstrip supply in 2023. Current industrial processes are focused on recovering cobalt and other valuable metals because, given lithium's current low price, it is economically unfavorable to recover it. As part of our efforts to create a process where the recovery of lithium is economically viable we have analyzed the current industrial processes. We have determined that, when applied to recycling automotive LIBs, they are needlessly energy intensive and complicated. In these processes whole LIBs are incinerated, cryogenically cooled, or shredded under an inert atmosphere in order to make their cells safe to open. Instead of such extreme measures, LIBs can be disassembled by automated processes, which recovers valuable electronics for reuse, their cells can be discharged, which recovers residual energy, and then can be opened safely in air.
Recent publications have discussed the potential for scarcity of materials needed for future engineering designs and manufacture 1,2, 3. In the case of a recent DOE report 1, materials needed for the ...production of green energy technologies were deemed as those needing study.
A major conclusion of these papers is that there is a need for recycling of materials that are designated as strategic or have a potential of becoming scarce. Lithium is one such material. It is critical to the battery industry, especially in compact consumer electronics (e.g. mobile phones and tablets) and in hybrid electrical and fully electrical vehicles. In this paper the role of lithium in electronics and vehicles is reviewed. Also reviewed are the reserves, projected mining capacity, and forecasted demand for lithium. Based on these three, it is predicted that there will be a shortage of lithium between 2021 and 2023 if lithium is not recycled 4.
Current lithium ion battery technologies recover little if any lithium and are energy intensive since they incinerate or shred batteries after they have been cooled in liquid nitrogen. This paper showcases a preliminary experiment where a battery was discharged by immersion in brine and safely opened manually. Pristine copped and the external protection circuit were easily recovered intact. Future experiments will attempt to recover lithium, aluminium, and the electrolyte with the aim of developing a method of recycling at room temperature that recovers all valuable materials, especially lithium.
The supply chain for metals used in manufacturing is usually from premanufacture (mining). Energy impact needs to be considered, with it being one of the five stressors that impact the environment. ...In this paper the energy needs for crushing and milling (comminution) are presented. A brief comparison is made with the energy needs for recycling of large scale waste products such as automobiles. A simple method for product designers, which uses Streamlined Life Cycle Analysis, is proposed for assessment of mining value chain impacts.
In metal powder compaction, density nonuniformity can be a source of flaws. Material models in finite element analysis for the prediction of density distribution still lack robustness and are ...computationally expensive. In this work, the Drucker–Prager cap (DPC) material model is implemented into the commercial finite element (FE) software ABAQUS/Explicit using the user-subroutine VUMAT. Yield functions in this material model are pressure-dependent and the curvature of the cap yield surface is high. This can cause numerical instability. We implemented a sub-increment technique to address this instability problem in a previous paper (Kashani et al., Trans North Am Manuf Res Inst SME 38:623–631,
2010
). The DPC model is also a non-smooth, multi-yield surface material model which has instability problems at the intersection of the yield surfaces; we adopted the corner region in the DPC material models for soils in order to remove instability and the results of which were presented in (Kashani et al., Trans North Am Manuf Res Inst SME 38:623–631,
2010
). The computational efficiency of the DPC material model was improved using a novel technique to solve the constitutive equations analytically which was shown in a previous paper by the authors (Kashani et al., Trans North Am Manuf Res Inst SME 38:623–631,
2010
). In this paper, experimental tests were conducted where cylindrically shaped parts were compacted from Distaloy AE iron-based powder to 7.0 g/cm
3
using 592 MPa of pressure. To measure local density, metallography and image processing were used to find the void area fraction of the surface. The FE results were compared to experimental results and it was shown that the FE analysis predicted local relative density within 3 % of the actual experimental measurements.
Single point incremental forming (SPIF) has higher formability limits than other sheet metal forming processes including stamping, and is therefore a desirable method of forming sheet metal ...components. To take advantage of this high formability it is necessary to understand how to maximise the limits through manipulation of parameters, increasing the likelihood of component success.
In this paper, a systematic quantitative literature review was undertaken analysing experiments and results from 35 papers that studied the effect of process parameters on formability in SPIF. Collective results are presented regarding material thickness, tool diameter, tool shape and type, step down, feed rate, spindle speed and rotation direction, and some parameter interactions. The analysis provides evidence to support the hypothesis of an ideal operating range for each parameter and interdependency of parameters. A lack of focus in the literature on parameter interactions was found. A framework for important experimental parameters is proposed based on the review.
Quantitative analysis of research presented in the literature about parameter effects on formability in SPIF.
Heat pumps in Ontario Szekeres, Alex; Jeswiet, Jack
International journal of energy and environmental engineering,
06/2019, Letnik:
10, Številka:
2
Journal Article
Recenzirano
Odprti dostop
More than 60% of household energy consumption in Ontario is for heating. Home heating needs in Ontario are driven by exterior temperatures that fluctuate throughout the day. Ontario’s electricity is ...generated from a different mix of primary energy sources from hour to hour. Using average hourly data for the electricity generation mix and hourly outside temperature data for each month of the year, we estimate residential heating loads and the electricity demands due to the use of three models of heat pump. Then we calculate the resultant greenhouse gas emissions and compare them to emissions if heat pumps are not used. We determine heating needs of single detached dwellings using prototypical average Ontario homes and building simulation software. Using heat pumps in all of these dwellings can reduce heating-related greenhouse gas emissions between 15% and 85% during January, the harshest month of the year. Using heat pumps could also reduce energy consumption for heating by between 12% and 68%, while requiring an approximate 5–25% increase in electricity demand. Heat pumps can provide a significant portion of home heat needs whilst reducing energy consumption and greenhouse gas emissions. Operating costs are lower than that of electric and oil heating, but similar to natural gas heating.
Heat pumps in Ontario Szekeres, Alex; Jeswiet, Jack
International journal of energy and environmental engineering,
06/2019, Letnik:
10, Številka:
2
Journal Article
Recenzirano
Odprti dostop
More than 60% of household energy consumption in Ontario is for heating. Home heating needs in Ontario are driven by exterior temperatures that fluctuate throughout the day. Ontario's electricity is ...generated from a different mix of primary energy sources from hour to hour. Using average hourly data for the electricity generation mix and hourly outside temperature data for each month of the year, we estimate residential heating loads and the electricity demands due to the use of three models of heat pump. Then we calculate the resultant greenhouse gas emissions and compare them to emissions if heat pumps are not used. We determine heating needs of single detached dwellings using prototypical average Ontario homes and building simulation software. Using heat pumps in all of these dwellings can reduce heating-related greenhouse gas emissions between 15% and 85% during January, the harshest month of the year. Using heat pumps could also reduce energy consumption for heating by between 12% and 68%, while requiring an approximate 5-25% increase in electricity demand. Heat pumps can provide a significant portion of home heat needs whilst reducing energy consumption and greenhouse gas emissions. Operating costs are lower than that of electric and oil heating, but similar to natural gas heating.
Home heating accounts for most of the residential energy use in Canada. While natural gas, oil-fired furnaces, and electric resistance are the dominant heating system choices, heat pumps have become ...a viable alternative. Heat pumps with lower minimum operating temperatures and better performance are increasing both their effectiveness and their number of hours of useful service. In this study, we apply System Dynamics to analyze the effects of technological development on the rate at which homeowners adopt residential air source heat pumps. We test the effects of low, moderate and high rates of technological development, as well as reduced electricity and carbon pricing on the predicted rate of adoption in Ontario. From the perspective of the use stage in life cycle assessment, we estimate energy savings and greenhouse gas emission reductions. We predict that using heat pumps will substantially reduce overall energy consumption, and in Ontario, where electricity is generated with little use of fossil fuels, it will also reduce greenhouse gas emissions.
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