An adaptive marine predator algorithm based optimization method for hood lightweight design

Zhang Chenglin,He Zhicheng,Li Qiqi,Chen Yong,Chen Shaowei,NIE XINYU 한국CDE학회 2023 Journal of computational design and engineering Vol.10 No.3

The lightweight design of the hood is crucial for the structural optimization of an entire vehicle. However, traditional high-fidelity-based lightweight methods are time-consuming due to the complex structures of the hood, and the lightweight results heavily rely on engineering experiences. To this end, an improved adaptive marine predator algorithm (AMPA) is proposed to solve this problem. Compared to the original marine predator algorithm (MPA), the proposed AMPA adapts to optimization problems through three enhancements, including chaotic theory-based initialization, a mixed search strategy, and dynamic partitioning of iteration phases. Experimental comparisons of AMPA, MPA, and eight state-of-the-art algorithms are conducted on IEEE CEC2017 benchmark functions. AMPA outperforms the others in both 30- and 50-dimensional experiments. Friedman and Wilcoxon’s sign-rank tests further confirm AMPA’s superiority and statistical significance. An implicit parametric model of the hood is generated, and the critical design variables are determined through global sensitivity analysis to realize hood lightweight. The stacking method is employed to construct a surrogate meta-model of the hood to accelerate the optimization efficiency of the vehicle hood. Utilizing the meta-model and the proposed AMPA, the hood mass is reduced by 7.43% while all six static and dynamic stiffness metrics are enhanced. The effectiveness of the proposed optimization method is validated through finite element analysis.

석탄 바닥재를 이용한 인공경량골재의 제조 및 경량 콘크리트에 적용

김강덕,강승구,Kim, Kang-Duk,Kang, Seung-Gu 한국결정성장학회 2008 한국결정성장학회지 Vol.18 No.5

The artificial lightweight aggregate (ALA) was manufactured in a rotary kiln at $1125^{\circ}C$ using green body formed by pelletizing the batch powder composing of coal bottom ash (CBA) produced from power plant, clay and dredged soil (DS). The TCLP (Toxicity characteristic leaching procedure) results showed that the dissolution concentration of heavy metal ions of ALA fabricated in this study was below the limitation defined by the enforcement regulations of wastes management law in Korea. The ALA containing 60$\sim$70 wt% CBA had a bulk density of 1.45$\sim$1.49 and a water absorption of 17.2$\sim$18.5 %. The impact values for oven-dry state and saturated-surface dry state of ALA were 27.4$\pm$1.3 and 23.4$\pm$2.6 % respectively. The 28-days compressive strength of concrete made with various ALA was $22.7\sim27.8 N/mm^2$. The slump of concrete with ALA containing CBA 60 and 70 wt% were 7.9 and 14.3 cm respectively. The unit weight of concrete made with any ALA fabricated in this study was satisfied with the standard specifications of lightweight concrete for the civil engineering and construction presented by Korea as below $1.84 ton/m^3$. 화력발전소에서 발생하는 석탄 바닥재(Coal bottom ash)를 준설토(Dredged soil) 및 적점토(Clay)와 혼합하여 조립기(Pelletizer)로 성형 후, 이를 로타리 킬른에서 $1125^{\circ}C$에서 소성하여 인공경량골재를 제조였다. 제조된 인공경량골재에 대한 중금속 용출 실험(TCLP) 결과, 폐기물 관리법 시행규칙의 중금속 검출량 기준치 이하로 나타났다. 바닥재가 60$\sim$70 wt% 첨가된 인공경량골재는 부피비중 1.45$\sim$1.49, 흡수율 17.2$\sim$18.5%의 값을 나타냈으며, 골재충격시험결과 건조 상태와 표건 상태의 충격값이 각각 27.4$\pm$1.3 및 23.4$\pm$2.6%를 나타내었다. 인공경량골재를 이용하여 제조된 콘크리트 공시체의 28일 압축강도는 첨가된 골재종류에 따라 $22.7\sim27.8 N/mm^2$ 이었다. 바닥재가 60 및 70% 첨가된 골재를 사용한 콘크리트의 슬럼프 값은 각각 7.9와 14.3 cm를 나타내었고, 단위용적질량은 골재조성에 상관없이 $1.84 ton/m^3$ 이하를 나타내어 토목 건축공사 표준시방서에 제시된 경량콘크리트 특성을 만족하였다.

상용차 경량 휠 허브 모듈의 구조적 안정성 평가

박은지(Eunji Park),남찬혁(Chanhyuk Nam),고웅희(Woonghee Ko),함규용(Gyuyong Ham),김성훈(Sunghoon Kim),최성욱(Sungwook Choi),이기주(Kiju Lee) 한국자동차공학회 2019 한국자동차공학회 학술대회 및 전시회 Vol.2019 No.11

With the strengthening of international environmental regulations, fuel economy regulations, and rising prices of energy resources, the development of lightweight materials and components for automobiles to improve fuel efficiency is being actively conducted. Compared to passenger cars, commercial vehicles that have a large load and long-distance operation are also developing technologies related to weight reduction to improve fuel efficiency. There is a growing interest in brake products, which are highly lightweight. Currently, the brake system of a medium-large commercial vehicle is shifting from a drum brake to a disc brake system that can provide braking safety and light weight. In the advanced automotive market in Europe, mass production of lightweight products using technologies such as aluminum hubs and dissimilar materials is being developed through new material application and optimal design technology. However, as the brake is a part directly connected to the safety of the vehicle, securing safety is an important factor in product development. In this paper, a model of a commercial vehicle wheel hub module consisting of three parts is presented for light weight, and the structural stability of the proposed lightweight wheel hub module is evaluated through analysis. In addition, the strain generated by the strain gauge was measured using a commercial brake dynamometer. The accuracy of the analytical model was improved through comparison with the analytical model.

다종재질 TWB 핫스탬핑 기술 개발

이광수(Kwangsu Lee),이윤정(Yunjeong Lee),김소연(Soyoun Kim) 한국자동차공학회 2022 한국자동차공학회 학술대회 및 전시회 Vol.2022 No.11

Automotive makers feel the necessity for strong lightweight solution because regulation of CO2 and fuel efficiency will tighten in the world. The most important factor for BIW lightweight is hot-stamping technology. So we developed new TWB hot-stamping technology using new material and new welding technology. The purpose of this technology is that body designer can combine various thickness and strength for lightweight. Many sectors participated for developed this technology. We developed new TWB welding technology using filler-wire and new hot-stamping material (tensile strength 980MPa). In addition, evaluation method of CAE simulation redefined for using new hot-stamping material and decision of formability in TWB hot-stamping. In the result, we applied new ‘B’ reinforcement outer panel through this technology, it can achieve lightweight and cost down.

단위중량 2,000㎏/㎥급 고강도 시멘트 복합체 개발을 위한 기초연구

정연웅(Yeon-Ung Jeong),임귀환(Gwi-Hwan Lim),강용학(Yong-Hak Kang),정상화(Sang-hwa Jung),김주형(Joo-Hyung Kim) 한국건설순환자원학회 2020 한국건설순환자원학회 논문집 Vol.8 No.4

본 연구에서는 단위중량 2,000㎏/㎥ 이하의 고강도 시멘트 복합체 제조기술 및 기초 물성을 탐구한다. 선행연구에서 제시한 초고성능콘크리트의 배합에서 잔골재를 경량 재료인 솔리드 버블과 경량잔골재로 치환하여 경량 고강도 시멘트 복합체를 제조기술을 제안한다. 솔리드 버블을 혼입한 시멘트 복합체는 밀도 2.0g/㎤ 이하에서 재령 28일 강도 116MPa∼141MPa의 고강도 발현이 가능한 것으로 나타났다. 경량잔골재를 사용하는 경우 솔리드 버블을 혼입한 시멘트 복합체보다 역학적 성능이 떨어지는 것으로 나타났다. 배합표상에서 계산된 단위용적중량과 경화된 시멘트 복합체의 밀도가 큰 차이를 보이지 않았으며, 이는 배합표상에서 계산된 단위용적중량을 통해 경화된 시멘트 복합체의 밀도를 추정할 수 있는 것을 보여준다. This study explores manufacturing technology and basic properties of high strength cement composites at 2,000㎏/㎥ of specific weight. It is suggested that lightweight-high strength cement composites can be produced by substituting silica sand in ulta-high performance concrete mixture with lightweight materials such as solid bubbles and lightweight fine aggregates. The 28-day compressive strengths of cement composites with solid bubbles were from 116MPa to 141MPa at below 2.0g/㎤ of unit density while the cement composites with lightweight aggregates possessed lower compressive strength and higher unit density. The specific weight calculated from mixture proportions did not have significant difference with unit density of hardened cement composites, indicating that unit density of hardened cement composites can be estimated from the specific weight in mixture proportions.

Experimental Evaluation of Relationship between Shear Deformation and Pinching in Lightweight-aggregate Reinforced Concrete Beams

Farrokh Aghamohammadzadeh,Hassan Afshin,Masoud Nekooei 대한토목학회 2019 KSCE Journal of Civil Engineering Vol.23 No.1

An experimental program was arranged to investigate the relationship between shear deformation and pinching in lightweightaggregate reinforced concrete beams under cyclic loading. Lightweight-aggregate reinforced concrete beams and their connection to column were selected for the purpose of this study and their flexural and shear behaviors experimentally were investigated. Damaged part of the beams was determined after the test. Using the results, values of beam tip displacement, curvature, and shear distortion in the plastic hinge region of beam were measured and components of shear and flexural deformation of the beam were calculated. Investigations were also performed on the effect of damage extension at the beam-column connection joint as well as effect of shear deformation on pinching increase. It was concluded that, in the lightweight-aggregate reinforced concrete beams in which the damaged part was extended to the beam-column joint, pinching was higher and also shear deformation has a larger contribution of the total beam deformation.

굴착복구용 속경성 경량기포 시멘트 모르타르의 최적 배합 도출을 위한 기초 물성 연구

안지환,전성일,An, Ji-Hwan,Jeon, Sung-il 한국도로학회 2017 한국도로학회논문집 Vol.19 No.1

PURPOSES : The objective of this study is to develop an optimized method of mix design for rapid-set lightweight-formed mortar mix. To achieve this objective, the workability, setting time, and compressive strength of mixes under various conditions of mix design were evaluated. METHODS : The water-bonder ratio, fly-ash substitution ratio, and forming agent injection amount were selected as design variables in the study. The fluidity, setting time, density, and strength of the mortar mix were considered as major evaluation criteria of the mixture, and were subsequently utilized to evaluate the characteristics of the mortar mix under various conditions. RESULTS : The observations made from the mix design process are as follows: 1) the air content and fluidity increase as the forming agent ratio and forming agent ratio increase, respectively; 2) the maximum air content is approximately 20%; 3) the accelerating agent decreases the fluidity of the mortar mix by 15% on average; 4) the forming agent injection ratio and fly-ash substitution ratio yield significant effects on the initial and final set times of the mortar mix; 5) as the forming agent injection ratio and fly-ash substitution ratio increase, the compressive strength of the mortar mix decreases; and 6) the 28-day compressive strengths of the forming agent injection ratio and fly-ash substitution ratio yield the most significant effects. CONCLUSIONS : It is concluded that the governing design variables for the rapid-set lightweight-formed mortar mix are the forming agent injection ratio and fly-ash substitution ratio.

Lightweight Energy Auction Smart Contract for Industrial Application

Allwinnaldo,Revin Naufal Alief,Muhammad Rasyid Redha Ansori,Ikechi Saviour Igboanusi,Jae Min Lee,Dong-Seong Kim 한국통신학회 2022 한국통신학회 학술대회논문집 Vol.2022 No.11

Electricity energy as one of the most, if not the most, essential aspects of human life in order to work and cycle well; energizing the minor part as an electronic device, way up to the significant and critical one, would not be possible to not requiring any electricity as the energy supply. No exception to the industrial and manufacturing sector, that colossal energy supply that is constantly reliably needed is so apparent. The condition imbalance of supply and demand, especially on industrial, could lead to numerous losses and significant financial disadvantages. Therefore, a solutive answer for the energy marketplace is needed to toss the imbalance of supplyand-demand issues. Blockchain-based smart contract of energy auction provides a secured auction system with underwhelming maintaining price for industrial to buy energy supply from an energy provider, safe and secured. It is a possible proposed smart contract that is developed to have a strongly secured, convenient, and lightweight.

경량합금 판재용 반복 하중 시험기 성능 평가

강유석(Y. S. Kang),서오석(O. S. Seo),Ngoc-Trung Nguyen,김헌영(Heon Young Kim) 한국소성가공학회 2012 한국소성가공학회 학술대회 논문집 Vol.2012 No.5

Recently, lightweight alloy sheet has been used widely in the field of automotive and electronic industries because of its lightweight. e.q. However, some difficulties exists in characterizing the material, poor formability and abnormal stress behavior. In this paper, a new cyclic loading tester is developed for characterization of constitutive equation and failure behaviors of Mg alloy sheet. Material tests including tension / compression / tension or compression / tension / compression test are performed to magnesium alloy sheet and construct a database of its material properties.

Estimation of lightweight aggregate concrete characteristics using a novel stacking ensemble approach

Kaloop, Mosbeh R.,Bardhan, Abidhan,Hu, Jong Wan,Abd-Elrahman, Mohamed Techno-Press 2022 Advances in nano research Vol.13 No.5

This study investigates the efficiency of ensemble machine learning for predicting the lightweight-aggregate concrete (LWC) characteristics. A stacking ensemble (STEN) approach was proposed to estimate the dry density (DD) and 28 days compressive strength (Fc-28) of LWC using two meta-models called random forest regressor (RFR) and extra tree regressor (ETR), and two novel ensemble models called STEN-RFR and STEN-ETR, were constructed. Four standalone machine learning models including artificial neural network, gradient boosting regression, K neighbor regression, and support vector regression were used to compare the performance of the proposed models. For this purpose, a sum of 140 LWC mixtures with 21 influencing parameters for producing LWC with a density less than 1000 kg/m³, were used. Based on the experimental results with multiple performance criteria, it can be concluded that the proposed STEN-ETR model can be used to estimate the DD and Fc-28 of LWC. Moreover, the STEN-ETR approach was found to be a significant technique in prediction DD and Fc-28 of LWC with minimal prediction error. In the validation phase, the accuracy of the proposed STEN-ETR model in predicting DD and Fc-28 was found to be 96.79% and 81.50%, respectively. In addition, the significance of cement, water-cement ratio, silica fume, and aggregate with expanded glass variables is efficient in modeling DD and Fc-28 of LWC.