scholarly journals Calibration of RC Columns Using Fiber Elements

2021 ◽  
Vol 4 (2) ◽  
pp. 205-213
Author(s):  
Fazil Abdulkadir Caglar ◽  
Tuba Tatar

Although experimental studies have proven as the most effective method, its high cost has provoked researchers to seek alternative approaches. The increase in computational power in the 21st century provides the opportunity to numerically model experimental studies with various programs. This study examines the comparison of force-based element and displacement-based element in columns using nonlinear fiber elements. Within the scope of the study, OpenSees program is employed for columns selected from the PEER (Structural Performance Database) site. The aim is to compare the employment of the FB element and DB elements in RC columns in terms of number of elements and integration points, to simulate the global behavior of the columns numerically, and to optimize the parameters that affect the results.

2005 ◽  
Vol 21 (2) ◽  
pp. 117-124 ◽  
Author(s):  
Y.-Y. Lin ◽  
K.-C. Chang ◽  
Y.-L. Wang

AbstractFor performance-based seismic engineering of buildings, the direct displacement-based seismic design method is different from the coefficient method used in FEMA-273 and the capacity spectrum method adopted in ATC-40. The method not only is a linear static procedure but also is applied to the design of new constructions. This paper concerns with experimental studies on the accuracy of the direct displacement-based design procedure. Experimental results of three reinforced concrete (RC) columns designed by the displacement procedure are presented and discussed through pseudo-dynamic tests and cyclic loading tests. From the tests, it is shown that the stiffness degrading factor of RC columns plays a key role. The direct displacement-based seismic design method can reliably capture the maximum displacement demand of the test RC columns if the stiffness degrading factor adopted in the displacement design method for RC material is adequate.


Author(s):  
Dion Marriott

This paper discusses the application of the Structural Performance factor (SP) within a Direct Displacement-Based Design framework (Direct-DBD). As stated within the New Zealand loadings standard, NZS1170.5:2004 [1], the SP factor is a base shear multiplier (reduction factor) for ductile structures, i.e. as the design ductility increases, the SP factor reduces. The SP factor is intended to acknowledge the better-than-expected structural behaviour of ductile systems (both strength, and ductility capacity) by accounting for attributes of response that designers are unable to reliably estimate. The SP factor also recognizes the less dependable seismic performance of non-ductile structures, by permitting less of a reduction (a larger SP factor) for non-ductile structures. Within a traditional force-based design framework the SP factor can be applied to either the design response spectrum (a seismic hazard/demand multiplier), or as a base shear multiplier at the end of design (structural capacity multiplier) – either of these two approaches will yield an identical design in terms of the required design base shear and computed ULS displacement/drift demands. However, these two approaches yield very different outcomes within a Direct-DBD framework – in particular, if SP is applied to the seismic demand, the design base shear is effectively multiplied by (SP)2 (i.e. a two-fold reduction). This paper presents a “DBD-corrected” SP factor to be applied to the design response spectrum in Direct-DBD in order to achieve the intent of the SP factor as it applies to force-based design. The proposed DBD-corrected SP factor is attractive in that it is identical to the SP relationship applied to the elastic site hazard spectrum C(T) for numerical integration time history method of analysis within NZS 1170.5:2004 [1], SP,DDBD = (1+SP)/2.


2015 ◽  
Vol 137 (1) ◽  
Author(s):  
Ashley A. Lloyd ◽  
Zhen Xiang Wang ◽  
Eve Donnelly

Heterogeneity of material properties is an important potential contributor to bone fracture resistance because of its putative contribution to toughness, but establishing the contribution of heterogeneity to fracture risk is still in an incipient stage. Experimental studies have demonstrated changes in distributions of compositional and nanomechanical properties with fragility fracture history, disease, and pharmacologic treatment. Computational studies have demonstrated that models with heterogeneous material properties predict apparent stiffness moderately better than homogeneous models and show greater energy dissipation. Collectively, these results suggest that microscale material heterogeneity affects not only microscale mechanics but also structural performance at larger length scales.


Author(s):  
Selcuk Aslan

Increasing number of cores in a processor chip and decreasing cost of distributed memory based system setup have led to emerge of a new work theme in which the main concern focused on the parallelization of the well-known algorithmic approaches for utilizing the computational power of the current architectures. In this study, the performances of the conventional parallel and cooperative model based parallel Artificial Bee Colony (ABC) algorithms on the deployment problem related to the wireless sensor networks were investigated. The results obtained from the experimental studies showed that parallelized ABC algorithm with the cooperative model is capable of finding similar or better coverage ratios with the increased convergence speeds than its serial counterpart and parallelized implementation in which the emigrant is chosen as the best food source in the current subcolony.


Life ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 774
Author(s):  
Hosna Mohammad Mohammad Sadeghi ◽  
Ida Adeli ◽  
Taraneh Mousavi ◽  
Marzieh Daniali ◽  
Shekoufeh Nikfar ◽  
...  

A slow rate of new drug discovery and higher costs of new drug development attracted the attention of scientists and physicians for the repurposing and repositioning of old medications. Experimental studies and off-label use of drugs have helped drive data for further studies of approving these medications. A deeper understanding of the pathogenesis of depression encourages novel discoveries through drug repurposing and drug repositioning to treat depression. In addition to reducing neurotransmitters like epinephrine and serotonin, other mechanisms such as inflammation, insufficient blood supply, and neurotoxicants are now considered as the possible involved mechanisms. Considering the mentioned mechanisms has resulted in repurposed medications to treat treatment-resistant depression (TRD) as alternative approaches. This review aims to discuss the available treatments and their progress way during repositioning. Neurotransmitters’ antagonists, atypical antipsychotics, and CNS stimulants have been studied for the repurposing aims. However, they need proper studies in terms of formulation, matching with regulatory standards, and efficacy.


2021 ◽  
Author(s):  
Gavin T. L. Brown ◽  
Anran Zhao

Interest in how learners understand, respond to, and value educational feedback has increased notably in the last two decades. Much of the current evidence of the impact or influence of feedback arises from self-report inventories. Self-report respondents are presumed to be well situated to report on their own experiences, attitudes, and behaviours. However, considerable validity threats exist in this method, which may limit the meaningfulness of self-reports. Consequently, many researchers are concerned about the disproportionate role self-reports play in informing our understanding of effective feedback. The validity of claims about learner self-reports on feedback depend on the credibility of the measures used. Inventories developed within the psychometric tradition are expected to provide theoretical and empirical evidence for the validity and reliability of the measures to support subsequent interpretations and decisions. This review provides a defense of the potential value of psychometric self-report data in informing the psychology of effective feedback. A systematic review of 14 feedback self-report inventories published in the 21st century found 25 empirical studies that replicate one or more of these inventories. Thirteen survey and 12 experimental studies were reviewed to provide a thematic analysis of the state of research. Seven studies used latent theory modeling to test the robustness of the MIMIC-based inventories, relying instead on estimates of scale reliability. Eight of 25 studies reported full replication of the inventory. Just four studies had an independent measure (academic achievement), with the vast majority of studies relating feedback inventories to self-reported constructs. Most effects were small and used small samples, which weakens reproducibility. The data showed that feedback perceptions have complex overlap with psychological control and competence beliefs, largely consistent with self-regulation of learning theory. Psychometric methods can improve the quality of research into how students understand, experience, think about, and use feedback that is given to them.


2020 ◽  
Vol 20 (2) ◽  
pp. 229-238 ◽  
Author(s):  
Ida K. Flink ◽  
Silje Reme ◽  
Henrik Børsting Jacobsen ◽  
Julia Glombiewski ◽  
Johan W.S. Vlaeyen ◽  
...  

AbstractBackground and aimsIn the spring of 2019, Professor Steven J. Linton, the founder of the Center for Health and Medical Psychology (CHAMP) at Örebro University, Sweden, formally retired. As a tribute to his scholarly work covering decades of influence and inspiration to the field of pain psychology, the research center organized a topical conference titled “Pain in the 21st century: Where do we come from and where are we going?”, which resulted in this state-of the-art synthesis. The aim of this declaration is to highlight lessons learned but not in the least is meant to inspire and guide our continued journey forward, developing pain psychology into the 21st century.MethodsSeveral collaborators of Professor Linton have summarized and reflected on the current state-of-the-art of pain psychology from the perspective of his input to the field, as well as on developments from the last years of advancements in pain psychology.ResultsThe topics have been divided into six themed sections covering the fear avoidance model, transdiagnostics, secondary prevention, risk- and protective factors, communication and contextual factors. The sections cover a broad spectrum, from basic experimental studies, integrating emotion and motivational theories into current theoretical models, to applied research on the effect of early interventions as well as sophisticated emotion-focused treatment models for pain patients with concurrent emotional ill-health.ConclusionsThere have been major advancements within pain psychology research during the last decades, moving the field towards a more comprehensive picture, taking emotional and motivational aspects into account to understand pain sufferers. Although psychologically informed interventions in general mainly focus on the individual, it has been put forward that pain management is highly influenced by the surrounding environment, including communication with health care providers, and the occupational and social context.ImplicationsProfessor Steven J. Linton has been at the forefront of pain psychology research during the last decades, and inspired by his work this journey will continue into the 21st century, with the ultimate goal of enhancing the understanding and treatment for all people suffering from persistent and disabling pain.


2020 ◽  
Vol 6 (1) ◽  
pp. 26-29
Author(s):  
Vaidya Pratigya Chauhan ◽  
◽  
Bhawna Dutt ◽  
Mahesh Vyas ◽  
S. K. Gupta ◽  
...  

Ayurveda provide a basic way of living to the people and mentioned the different “Charyas” to be done by the individuals in day to day life as well as this ancient science garlanded us with the knowledge and code of conducts to conduct different type of studies like experimental studies, survey studies etc. In this sequence, Janapadodhwansa, a chapter describes in Vimana Sthana by Acharya Charaka is considered as the chapter of epidemiological study. Where he explained the whole concept on handling the situation of pandemic state. Now, a days It is evident to notify the Pandemic state of China and different countries due to the virus knows as corona virus, which is responsible and causes pressure on societies and health care system. This is the first pandemic condition of 21st century which requires internationally unified cogent and collective actions by the individuals, communities, commercial bodies etc. Due to the novelty of the virus, there is no treatment known and no vaccination is available. Only social distancing and other preventive measures are tolls used to deal this emergency. And hence, this condition can be correlated with Janapadodhwansa. And Rasayana is one of them, which provide the strength against the viral condition and improve the immune response towards this pandemic disease. This article aims to provide information about role of Rasayana dravyas (Gudhuchi, Amalaki and Haridra) which can be in cooperated in day to day life and act as immune modulators.


DYNA ◽  
2019 ◽  
Vol 86 (208) ◽  
pp. 227-233
Author(s):  
Carlos Rolando Rios Soberanis ◽  
Victor Jose Ley Paredes ◽  
Emilio Perez Pacheco ◽  
Carlos Emilio Vinajera Reyna ◽  
Shuichi Wakayama ◽  
...  

Mayan buildings have been the subject of significant archaeological and architectural research; however, so far there have been no relevant references concerning structural or mechanical behavior. Ancient Mayan constructors used calcareous rocks to build temples and housing that were placed systematically to withstand mechanical loads in the structures. This paper studies the mineralogical and mechanical characteristics of calcareous stony material that formed part of Mayan archeological vestiges in Yucatan area. The orientation of the rocks´ geological strata was taken into account to study mechanical behavior from cylindrical cores in compressing test. On the other hand, bars were also manufactured to simulate lintel or architrave structural performance. Compression and bending tests confirmed a high influence of the geological layer orientation, since the mechanical properties of such rocks were found to vary with direction. Acoustic emission was used to provide information referring to onset and propagation of damage in cylinder and bar samples.


2021 ◽  
Vol 878 ◽  
pp. 127-133
Author(s):  
J. Selejdak ◽  
Y. Blikharskyy ◽  
R. Khmil ◽  
Z. Blikharskyy

This paper presents the experimental testing of eccentrically compressed reinforced concrete columns. There are experimental results of crack resistance of non-strengthened (control) and strengthened RC columns in the tension zone. The columns were strengthened by carbon fiber reinforced polymers (CFRP). As a result of experimental studies with the columns strengthened by CFRP, we obtain that the width of their crack decreased by an average of 33%. The eccentric compression load of the crack’s appearance increased from 40 kN to 60 kN for strengthened columns.


Sign in / Sign up

Export Citation Format

Share Document