Modeling the effects of high strain rate loading on RC columns using Arbitrary Lagrangian Eulerian (ALE) technique

In recent years, many studies have been conducted by governmental and nongovernmental organizations across the world in an attempt to better understand the effect of explosive loads on buildings in order to better design against specific threats. This study is intended to contribute to increase the knowledge about how explosions affect reinforced concrete (RC) columns. In this study, a nonlinear model is developed to study the blast response of RC columns subjected to explosive loads. Numerical modeling of RC column under explosive load is presented using advanced finite element code LS DYNA. The obtained numerical model is validated with the experimental test and the results are in substantial agreement with the experimental data. ALE method for blast analysis is presented in the current research. The effects of scaled distance on the damage profile of RC columns are investigated. The results demonstrate that the level of damage increased with describing the scaled distance. Also the results shown duration for the blast loading, and hence the impulse, varies with charge masses at the specified scaled distance. Higher magnitude charge masses produced longer blast loading durations than lower magnitude charge masses. This means that at the same scaled distance, a charge mass of higher magnitude produced a higher impulse than the lower magnitude charge mass. The findings of this research represent the scaled distance is an important parameter that should be taken into account when analyzing the behavior of RC columns under explosive effects. The data collected from this research are being used to improve the knowledge of how structures will respond to a blast event, and improve finite element models for predicting the blast performance of concrete structures.Peer Reviewe

NUMERICAL PREDICTION OF COMPOSITE BEAM SUBJECTED TO COMBINED NEGATIVE BENDING AND AXIAL TENSION

The present study has investigated the finite element method (FEM) techniques of composite beam subjected to combined axial tension and negative bending. The negative bending regions of composite beams are influenced by worsen failures due to various levels of axial tensile loads on steel section especially in the regions near internal supports. Three dimensional solid FEM model was developed to accurately predict the unfavourable phenomenon of cracking of concrete and compression of steel in the negative bending regions of composite beam due to axial tensile loads. The prediction of quasi-static solution was extensively analysed with various deformation speeds and energy stabilities. The FEM model was then validated with existing experimental data. Reasonable agreements were observed between the results of FEM model and experimental analysis in the combination of vertical-axial forces and failure modes on ultimate limit state behaviour. The local failure modes known as shear studs failure, excess yielding on steel beam and crushing on concrete were completely verified by extensive similarity between the numerical and experimental results. Finally, a proper way of modelling techniques for large FEM models by considering uncertainties of material behaviour due to biaxial loadings and complex contact interactions is discussed. Further, the model is suggested for the limit state prediction of composite beam with calibrating necessary degree of the combined axial loads

A Case Study of Maintenance Management Systems in Malaysian Complex and High-rise Industrialized Building System Buildings

The implementation of a maintenance management system faced many issues due to defect repetition and lack of proper structure management planning. A case study was undertaken among complex and high-rise Industrialised Building System (IBS) buildings in Malaysia to identify a key of problem areas and to establish elements of good practice. The study evaluated the performance of the existing maintenance management system used by complex and high-rise IBS buildings to determine whether there is a need to improve current maintenance management system. Results showed that existing performance is far below best practice standards and that the use of emerging technology such as Building Information Modelling (BIM) is very limited. This led to the development of a key feature of the maintenance management system using emerging technology to assist engineers at complex and high-rise IBS buildings to improve their existing approaches to maintenance management. Keywords: Maintenance management; process; Malaysia; IBS buildings; BIM JEL Classifications: O1; O2; O

FINITE ELEMENT ANALYSIS OF COMPOSITE PLATE GIRDERS WITH A CORRUGATED WEB

Corrugated steel plates are widely used in pre-stressed box girder bridges due to its ability to achieve an adequate shear buckling resistant and reduce the dead weights. The present study aimed to determine the static behaviour of two and four panels composite plate girder with a corrugated web by using LUSAS software. The numerical models were validated according to the outcomes of a previous experimental test. The validation results indicated a good consistency in terms of load-deflection response, shear strength and failure mode. Intensive parametric studies were carried out to determine the effects of corrugation angle (), corrugated web thickness (), flange thickness () and concrete strength on the behaviour of composite plate girder. The results indicated a positive increase in the shear strength and change in the failure mode of the both investigated girders with the increase of corrugation angle, web and flange thickness. On the other hand, a slight effect was noted for the concrete strength on the shear resistance and failure mode of the composite plate girders with corrugated webs, therefore, a considerable reduction in the construction cost might be achieved by utilizing a normal concrete strength in the design

Behaviour of prestressed box beam strengthened with CFRP under effect of strand snapping

U radu se analizira ponašanje prednapete sandučaste grede ojačane polimerom s ugljičnim vlaknima (CFRP) za slučaj pucanja prednapetih užadi. Tri vanjske prednapete sandučaste grede ispitane su do sloma. Analiza je provedena s naglaskom na nosivost, širinu i obrazac širenja pukotina, te na torzijsku čvrstoću grede. Rezultati pokazuju da primjena CFRP-a dovodi do znatnog smanjenja progiba i do povećanja nosivosti u slučaju pucanja užadi. Pukotine se ne pojavljuju na dnu grede na koju je postavljen CFRP, a bitno je povećana i krutost grede na torziju.The study aims to evaluate behaviour of a prestressed box beam strengthened with the Carbon Fibre Reinforced Polymer (CFRP) under the snapping of prestressed strands. Three external prestressed box beams are tested until failure. The evaluation focuses on the load carrying capacity, cracks pattern and width, and torsional capacity of the beam. The results show that the use of CFRP causes significant reduction of beam deflection and an increase of its loading capacity under snapping effects. The cracks do not appear at the bottom of the beam where the CFRP is placed, and the torsion stiffness of the beam increases considerably

Exploration and verification of fourth industrial revolution generic skills attributes for entry-level civil engineers

The fourth industrial revolution (4IR) requires the workforce to be equipped with new skills when existing skills need to be upgraded or improved because they are no longer in line with technological advancement in 4IR. Thus, it is crucial to determine what the new skills or 4IR skills are that can help the future workforce obtain a job after graduation. This study aimed to explore and verify the attributes of nine 4IR generic skills (GS4IR) for entry-level civil engineers in Malaysia by using a qualitative approach. An interview session was conducted with five senior engineers in the civil engineering (CE) field and three experts (two engineers in CE and one lecturer in CE faculty) for reliability data verification. The interview data were analyzed using coding analysis and presented in a matrix table. The results show 76 items identified as attributes of nine GS4IR constructs. Next, the verification of the constructs and attributes of GS4IR was obtained from Fleiss Kappa's reliability analysis to determine the overall approval index. The results of the analysis revealed an overall Kappa coefficient value of 0.61, which indicates a good level of agreement. The findings of this study consist of 58 attributes for nine constructs of GS4IR approved after the inter-rater reliability among the experts. The findings from this study are beneficial for the development of a framework of 4IR generic skills for civil engineering graduates as guidance to instill new skills in producing future engineers

Penerokaan spesifikasi kemahiran generik 4IR bagi graduan kejuruteraan awam berdasarkan perspektif daripada industri

Gelombang teknologi baharu yang dikenali sebagai revolusi perindustrian 4.0 (4IR) diiringi dengan penggunaan robotik dan pengautomasian menyebabkan perubahan terhadap permintaan tenaga buruh dan bidang pekerjaan. Profesion jurutera awam merupakan salah satu daripada 53 bidang pekerjaaan kritikal bagi membangunkan ekonomi negara dalam mendepani arus cabaran 4IR. Namun begitu, peratusan bilangan jurutera awam baharu yang diterima bekerja masih lagi rendah disebabkan oleh faktor ketidaksepadanan kemahiran generik sekaligus menyebabkan masalah pengangguran dalam kalangan graduan kejuruteraan awam (KA) masih lagi berlaku. Oleh itu, kajian ini dilaksanakan untuk meneroka spesifikasi yang terperinci mengenai kemahiran generik 4IR (KG4IR) bagi graduan kejuruteraan awam berdasarkan perspektif daripada pihak industri kejuruteraan awam. Kajian ini menggunakan pendekatan kualitatif melalui temu bual semi berstruktur atas talian terhadap lima orang pakar bidang KA berdasarkan protokol temu bual. Dapatan temu bual dianalisis menggunakan sistem kod untuk mengeluarkan kategori dan tema bagi membentuk spesifikasi KG4IR. Hasil analisis mendapati bahawa sembilan tema KG4IR telah diperolehi iaitu kemahiran komunikasi, penyelesaian masalah, kepimpinan, kepintaran emosi, kreativiti, pemikiran kritikal, kebolehsuaian, digital dan pengurusan bersama perincian daripada kategori untuk membentuk spesifikasi KG4IR yang sesuai bagi graduan KA. Melalui spesifikasi KG4IR yang terperinci ini, ianya dapat dijadikan panduan bagi penerapan KG4IR oleh pihak pemegang taruh (IPT, pihak industri) untuk menghasilkan graduan kalis masa hadapan yang mampu bekerja dalam suasana pekerjaan 4IR selari dengan inspirasi Kerangka Pendidikan Tinggi 4.0 oleh Kementerian Pengajian Tinggi Malaysia.

Numerical Study of Structural Performance and Wind Flow Dynamic Behavior for PPVC Steel Modular Construction (MSC) under Various Extreme Wind Loads

PPVC modular construction building has become one of the most recent construction technologies in the civil engineering sector and has piqued researchers’ interest. Few published studies consider the overall structural response to extreme wind load. As a result, there is a lack of appropriate design for PPVC modular systems under extreme wind standards. However, the existing literature has not yet studied the wind flow dynamic behaviors of PPVC modular steel construction (MSC) systems subjected to extreme wind loads. This paper, therefore, presents a numerical investigation into the structural performance and wind flow dynamic behavior of innovative PPVC modular steel construction (MSC) systems under extreme wind loads. The numerical technique varied in comparison with previous studies. The results showed that the suggested novel (MSC1) modular system is applicable to prevention of extreme wind action up to cyclone 2nd degree, the high story drift resistance compared with previous research, high stiffness performance, and overall strain energy. Additionally, the actual wind velocity surrounding (MSC2) was 31.5% higher compared to the Saffir–Simpson wind speed scale, and the 1.5 wind speed safety factor was suggested