Mehdi Shokouhian

Numerical study on the cyclic response of AFRP reinforced columns with externally unbonded energy dissipaters

Abstract Fiber-reinforced polymer bars are gaining increased use in the construction market as a replacement to steel reinforcement for concrete structures. However their use as compression members is limited due to their mechanical properties, typically low flexural rigidity, so that local buckling may occur relatively at low stress levels. Their premature rupture in reinforced concrete (RC) columns could be eliminated by enhancing the columns’ response elastically and concentrating damage to the externally installed, replaceable post-tensioned structural fuses. This paper is part of a larger numerical and experimental investigation to develop and validate design methods for a rocking aramid fiber reinforced polymer (AFRP) reinforced concrete column. The numerical study, implemented using the Extreme Loading for Structures software, consists of a total of thirteen columns. The columns were subjected to axial load followed by cyclic lateral load up to failure to examine the effectiveness of the rocking connection and overall response. The effect of key variables such as longitudinal bar ratio, structural fuse sizes and tie spacing was investigated. Ductility and energy dissipation gains of the rocking AFRP RC columns were compared to that of the conventionally reinforced steel column, and expected performance of the rocking connection was achieved.

Performance Evaluation in the Computer-Adaptive Version of the Enginer-in-Training (EIT) Examination at Morgan State University

The Engineer-in-Training (EIT) exam is the first step to licensure as a professional engineer in the United States. Currently, the EIT Computer Based Testing (CBT) is generally perceived as a positive trend towards a more innovative and constructed response assessment task, which evaluates understanding in disciplinary knowledges, providing accessibility, unbiasedness and speedier test delivery for statewide assessment. This paper describes the interface design of a Computer Based Testing environment (FEBooth) as a testing modality at Morgan State University (MSU), its implementation, advantages over the paper based assessment (PBA) testing and evaluation or analysis of performance and, where appropriate, additional issues such as student’s perception of this method of assessment. To provide reliable measurements of student performance which, as well as having predictive value for the real Civil EIT exam, a total of 20 questions with short answers (SA) and multiple choices (MC) were administered to 90 graduating seniors in 2016. Strong influence on performance resulted from student learning gain from subjects in classroom and perceived ability to use FEbooth successfully which affected their behavioral response. Findings revealed preference to the paper based testing; however, 65% of the students exhibited computer anxiety resulting in slower task completion and poor performance. The study identified 35% and 55% of the students passed at first attempt while the likelihood of success increased to 56% and 68% in their second attempt of the CBT FEBooth and PBA, respectively. INTRODUCTION During the past few years, computerized testing (CBT) has gained popularity as an assessment modality and this has been implemented in occupational fields for licensure, certification, and psychological tests. 2 Test security, ability to create randomized questions from vast question pools, utilize encrypted databases for stored questions and immediate responses are great advantages of the CBT. 9 The Fundamentals of Engineering (FE or EIT) exam, the first step to becoming a professional engineer (P.E.), is designed for recent graduates in the United States. The computer version of the FE offers innovation in testing and assessment as it can be taken independent of time (administered year-round at NCEES-approved test centers) and the FE test developers can subject individual candidates to the same set of test conditions. So far, the shift to computer-based testing is believed to have accommodated increase in the number of test takers across the United States. 6 Conceivably though, research has not authenticated performances based on behaviors such as computer anxiety and slower task completion in comparison to the previously administered paper-based EIT exams. Frustrations from examinees are likely to occur in the CBT than on traditional paper-based exams due to concerns over constraints such as degree of computer literacy, test difficulty, questions being tailored to examinee ability levels, inability to skip and review questions and change answers. Whilst accredited training centers and hundreds of FE practice books are available, their assessment framework and test interface features differ from the real-administered EIT exam. In addition, familiarization with exam format and less comfortable test environment could hinder good test performance in CBT exams. Cognitive concerns such as ill preparation, thought disruptions and how others view the examinee if he/she does poorly raises anxiety. Since the EIT exam is not yet a self-adapted testing, poor performance could be as a result of the level of difficulty of test questions. Student’s outcome in the EIT CBT exam, just like other computerized testing, would largely depend on student learning gain on test areas. Student achievement is the status of subject-matter knowledge. Adequate preparation by students for the EIT exam would influence outcomes and scores which depends on learning process variables such as availability of technology for learning before the real exam is taken, including time specifications for understanding subject matter. LITERATURE REVIEW Computerized testing, a next-generation way of administering tests, provides numerous benefits leading to higher productivity in testing not experienced in traditional test designs such as the paper and pencil assessment format. Despite indications of indifference in the past about the advent of CBT and the opportunities it creates, increase in the use of such innovations as the internet has gradually pushed for support of computerized testing. CBT is particularly implemented in licensure and certifications due to the standardization of test administration conditions, customized feedback, test security, and immediate reporting as a result of advanced technological capacities. Evidence from early studies suggests that success in computer based assessment is highly dependent on examinees being adequately accustomed to the format in which the examination is administered. International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 http://www.ijert.org IJERTV6IS040438 (This work is licensed under a Creative Commons Attribution 4.0 International License.) Published by : www.ijert.org Vol. 6 Issue 04, April-2017