Effect of Top Sheet Materials on Joint Performance of Self-Piercing Riveting

Karim Md Abdul,Murugan Sivaprasad,배기만,백종진,지창욱,노우람,이한주,Jang Will,김덕봉,박영도 대한용접접합학회 2022 대한용접·접합학회지 Vol.40 No.6

Three types of self-piercing riveting (SPR) joints, i.e., steel/aluminum, carbon fiber reinforced polymer (CFRP)/ aluminum, and aluminum/aluminum, were constructed using three different top sheet materials with the same alumi- num alloy as the bottom sheet. The effects of the top sheet material on the joint quality and mechanical behavior were evaluated. The top sheet materials’ characteristics dominate the rivet piercing process and the consequent inter- lock distance. The high-strength steel top sheet requires a comparatively higher rivet setting force and induces early flaring of the rivet tail, resulting in a larger interlock distance. Though the CFRP needs the highest rivet setting force to penetrate the rivet through the CFRP fibers, the CFRP/aluminum joint exhibits the smallest interlock distance be- cause of the SPR process-induced damages to the CFRP and subsequently less flaring of the rivet tail. In strength tests, the damaged CFRP sheet resulted in rivet head pullout of the CFRP/aluminum joints, which exhibited the low- est lap-shear and cross-tension strengths. In contrast, the steel/aluminum joints demonstrated the highest strengths because of their comparatively larger interlock distances. In addition to the experimental analysis, simulations re- vealed the rivet penetration and flaring mechanisms with various top sheet materials, and their respective joint qual- ity and strengths.

Friction Effect of Rivet Coating Materials on Joining Process and Mechanical Performance of Self-piercing Riveted Joints

Md Abdul Karim,Jin-Hee Bae,Dong-Hyuck Kam,Cheolhee Kim,Yeong-Do Park 대한용접·접합학회 2019 대한용접학회 특별강연 및 학술발표대회 개요집 Vol.2019 No.5

A Review on Welding of Dissimilar Metals in Car Body Manufacturing

Md. Abdul Karim,Yeong-Do Park 대한용접·접합학회 2020 대한용접·접합학회지 Vol.38 No.1

This paper presents a comprehensive study of the metallurgical challenges of welding dissimilar metals. It also describes the important factors in dissimilar welding which need to be considered for automotive applications. It further investigates effective approaches to overcome these present challenges. Steels, aluminum alloys, and magnesium alloys are widely used metals in car bodies. However, it is difficult to weld these dissimilar metals and achieve good joint quality, due to their inherent disparate properties. The formation of brittle, crack sensitive and corrosion susceptible intermetallic phases is the main obstacle to dissimilar weld quality. Various approaches have been attempted by many researchers to enhance the performance of dissimilar welds. The most notable efforts include the application of interlayers, cover plate, least heat input, a combination of welding and mechanical joining, and alloying elements of filler metals. Based on considerations of joint performance, production cost and time, present industry infrastructure, and so on, the most effective and feasible approaches were identified which required the least amount of heat input, and the appropriate filler metal alloying elements.

Assessment of Mechanical Performance and Corrosion Behavior of CFRP/Aluminum Self-piercing Riveted Joints for Different Rivet Coatings

Md Abdul Karim,Jin-Hee Bae,Dong-Hyuck Kam,Nam-Ki Jeon,Cheolhee Kim,Chanyoung Jeong,Yeong-Do Park 한국자동차공학회 2018 한국자동차공학회 학술대회 및 전시회 Vol.2018 No.11

Critical Influence of Rivet Head Height on Corrosion Performance of CFRP/Aluminum Self-Piercing Riveted Joints

( Md Abdul Karim ),( Jin-hee Bae ),( Dong-hyuck Kam ),( Cheolhee Kim ),( Yeong-do Park ) 한국부식방식학회(구 한국부식학회) 2019 Corrosion Science and Technology Vol.18 No.3

This study investigates how rivet head height affects the corrosion performance of carbon fiber reinforced plastic (CFRP) to aluminum alloy self-piercing riveted joints. Specimens with two different head heights were prepared. A rivet head protruding out of the top CFRP laminate forms the proud head height while a rivet head penetrating into the top CFRP generates the flush head height. The salt spray test evaluated corrosion performance. The flush head joints suffered from severe corrosion on the rivet head. Thus, the tensile shear load of flush head joints was substantially reduced. Electrochemical corrosion tests investigated the corrosion mechanisms. The deeper indentation of the flush head height damaged the CFRP around the rivet head. The exposure of damaged fibers from the matrix increased the cathodic potential of local CFRP. The increased potential of damaged CFRP accelerated the galvanic corrosion of the rivet head. After the rivet head coating material corroded, a strong galvanic couple was formed between the rivet head base metal (boron steel) and the damaged CFRP, further accelerating the flush rivet head corrosion. The results of this study suggest that rivet head flushness should be avoided to enhance the corrosion performance of CFRP to aluminum alloy self-piercing riveted joints.

Evaluation of Noise Environment and Noise Mapping with ArcGIS in Chittagong City, Bangladesh

Md. Abdul Aziz,Ahasanul Karim,Md. Mehedi Hassan Masum,Kazi Kader Newaz 대한환경공학회 2021 대한환경공학회지 Vol.43 No.4

Objectives : Noise pollution in Chittagong City of Bangladesh is a big concern because of huge population growth and urbanization. The objective of the study was to evaluate and mapping the noise levels in twelve locations of this city at different periods. Methods : Noise level data were collected at various locations by a precision grade sound level meter and the noise pollution parameters (Lmin, LAeq,2h and Lmax) were calculated. Furthermore, the noise pollution maps of Chittagong City were developed using geographical information system to address the locations which are prone to the environmental hazards. Results and discussion : The study revealed that the average noise levels were 64.6, 76.9, and 75.5 ㏈(A) for residential, commercial and silence zones, respectively. The interpolated noise maps showed that noise environment of this city was unsatisfactory, especially, in the areas of New Market, Nasirabad, and Bawa School & College were exposed to high noise pollutions. The afternoon and evening periods were experiencing higher noise pollution in the commercial and silence zones than the morning period of the day. Conclusions : The study suggests that the noise levels are above the acceptable limit and hence urgent measures should be taken into consideration to control the level of noise pollution in the city.

Genotypic Variability in Plant Water Status of French Bean under Drought Stress

Apurba Kanti Choudhury,Md. Abdul Karim,Md. Moynul Haque,Qazi Abdul Khaliq,Jalal Uddin Ahmed,Md. Mofazzal Hossain 한국작물학회 2011 Journal of crop science and biotechnology Vol.14 No.1

Seven genotypes of French bean (Phaseolus vulgaris L.) were evaluated under semi-controlled conditions at the Bangabandhu Sheikh Mujibur Rahman Agricultural University, Bangladesh to analyze genotypic variability in leaf water status under water stress. The plants were grown under two moisture regimes, viz. 80% field capacity (FC) and 50% FC throughout the growing season. The genotypes showed significant variation in water relation traits. Genotypes BB24 and BB43 maintained higher relative water content (RWC), but lower turgid weight/dry weight ratio (TW/DW) and water uptake capacity (WUC). When drought susceptibility index (DSI) among the genotypes was considered, BB24 was found the most tolerant to drought and BB04 was the most susceptible one. A close positive relationship between leaf TW/DW and DSI under drought was recorded (R2 = 0.627). Leaf TW/DW was decreased considerably due to water stress by 10% in genotype BB24 followed by BB43 (13%), and both BARI bushbean-2 and BB04 (19%). Stomatal aperture and whole plant transpiration rate were found minimal in the BB24 and BB43 compared to that of BB04 and BARI bushbean-2. Considering these water relation traits, genotypes BB24 and BB43 may be considered as relatively tolerant to tissue dehydration. The study also revealed that the TW/DW, WUC, stomatal aperture, and whole plant transpiration rate was negatively and significantly associated with yield; however, the RWC was positively correlated with yield under water stress conditions.

Genotypic Variability in Plant Water Status of French Bean under Drought Stress

Choudhuryl, Apurba Kanti,Karim, Md. Abdul,Haque, Md. Moynul,Khaliq, Qazi Abdul,Ahmed, Jalal Uddin,Hossain, Md. Mofazzal 한국작물학회 2011 Journal of crop science and biotechnology Vol.14 No.1

Seven genotypes of French bean (Phaseolus vulgaris L.) were evaluated under semi-controlled conditions at the Bangabandhu Sheikh Mujibur Rahman Agricultural University, Bangladesh to analyze genotypic variability in leaf water status under water stress. The plants were grown under two moisture regimes, viz. 80% field capacity (FC) and 50% FC throughout the growing season. The genotypes showed significant variation in water relation traits. Genotypes BB24 and BB43 maintained higher relative water content (RWC), but lower turgid weight/dry weight ratio (TW/DW) and water uptake capacity (WUC). When drought susceptibility index (DSI) among the genotypes was considered, BB24 was found the most tolerant to drought and BB04 was the most susceptible one. A close positive relationship between leaf TW/DW and DSI under drought was recorded ($R^2=0.627$). Leaf TW/DW was decreased considerably due to water stress by 10% in genotype BB24 followed by BB43 (13%), and both BARI bushbean-2 and BB04 (19%). Stomatal aperture and whole plant transpiration rate were found minimal in the BB24 and BB43 compared to that of BB04 and BARI bushbean-2. Considering these water relation traits, genotypes BB24 and BB43 may be considered as relatively tolerant to tissue dehydration. The study also revealed that the TW/DW, WUC, stomatal aperture, and whole plant transpiration rate was negatively and significantly associated with yield; however, the RWC was positively correlated with yield under water stress conditions.

AUGMENTATION OF MARITIME INTERACTIVE TEACHING MODEL TOWARDS SUSTAINABLE DEVELOPMENT GOAL AND INDUSTRIAL REVOLUTION 4.0

Noorul Shaiful Fitri ABDUL RAHMAN,Noor Apandi OSNIN,Rudiah MD HANAFIAH,Mohd Rahimi ABDUL HALIM,Shahriman ABDUL HAMID,Nur Hazwani KARIM 국제이네비해양경제학회 2019 International Journal of e-Navigation and Maritime Vol.13 No.1

The manner in which education will be delivered in the 21st-century has often been debated. Various literature has agreed that an interactive teaching and learning method is required in parallel with the emergence and development of cyber technology. The conventional method of teaching should be reconstituted to emphasize aspects associated with innovation and creativity in attracting the attention of students in learning. Despite the current Malaysian education emphasize the learning features that include 1) Creative thinking, 2) Critical thinking, 3) Collaboration, 4) Character and 5) Communication. However, 21st-century approach requires exposure, skills, and creativity to be implemented by the Malaysian educators. Therefore, the aim of this study is to propose a new maritime interactive teaching model towards a Sustainable Development Goals (SGDs) and industrial revolution 4.0. Three (3) secondary schools around Terengganu in Malaysia were chosen to participate in a pilot case study. The results of the study found that more than 90% of students now understand more about the maritime industry based on their acquired knowledge and education in this area. While, more than 70% of students described that this method of teaching is appealing. Maritime education innovative learning through an interactive learning model was successfully achieved based on the findings of this study, called the ‘Mariner’s Fantasy’. Additionally, through the inspirations of IR 4.0 and the Malaysia Education Development Plan, 2013-2025, the study has demonstrated the usefulness of the Maritime Education Innovative Learning (MEIL) program through an interactive learning method, in enhancing the delivery of maritime education by adopting an effective teaching-based approach.

In vivo the antioxidative extract of Averrhoa carambola Linn. leaves induced apoptosis in Ehrilch ascites carcinoma by modulating p53 expression

Ayesha Siddika,Tasnim Zahan,Lipy Khatun,Md. Rowshanul Habib,Md. Abdul Aziz,A. R. M. Tareq,Md. Habibur Rahman,Md. Rezaul Karim 한국식품과학회 2020 Food Science and Biotechnology Vol.29 No.9

This study was designed to evaluate the antioxidantactivity of methanol extract of Averrhoa carambollaLinn. leaves (MELA) using DPPH˙ and ABTS˙+ free radicalscavenging assays whereas its antineoplastic effectagainst Ehrlich ascites carcinoma (EAC) was assed usingviable cell count, life span, body weight gain and hematologicalparameters of experimental mice. Results showedthat rich phenolic and flavonoid content of MELA hadmoderate dose dependent free radical scavenging activity(IC50: 62.0 lg/mL for DPPH˙ and 6.0 lg/mL for ABTS˙+). In vivo antineoplastic assay, MELA significantly(P\0.05) decreased viable cells and body weight gain,increased the survival time and restored altered hematologicalprofiles of cancer cell bearing mice. Fluorescencemicroscopic view of EAC cells derived from MELA-treatedgroup showed apoptotic characteristics and this observationwas also supported by overexpression of proapoptoticgenes coding p53 and Bax proteins in treatedcancer cells. The anti-apoptotic genes coding Bcl-2 proteinwas also absent in treated EAC cells as compared with thecontrol. Moreover, phytochemical profiles of MELA asidentified by GC/MS analysis are also consistent with itsactivities.