Performance of Enhanced Steel Beam-Column Welded Connections for Seismic Resistance

2021 ◽  
Vol 6 (6) ◽  
pp. 58-64
Author(s):  
W. Aboalriha
Keyword(s):  
Weld Zone ◽  
Hysteresis Loops ◽  
Life Cycles ◽  
Maximum Strain ◽  
Test Results ◽  
Element Analysis ◽  
Gusset Plate ◽  
Crack Location ◽  
The University ◽  
Cycles To Failure

This paper presents and discusses the development of a numerical model which investigates the enhancement of overall stiffness and stress distribution in welded connections under cyclic loading. The structure under investigation, described in four fully welded T-joint (BCC5) specimens. The four specimens were modeled under different displacement loading using a finite element analysis program Solidworks and Ansys software in conjunction with test data obtained from the University of Lisbon, which was validated with the test results by matching the hysteresis loops, maximum high strain, and maximum stress at the crack location steel joint specimens. The comparison between the analysis and test results showed good agreement and also showed that the maximum strain in the enhanced model is less than the maximum strain on the base model, and the location of maximum strain is moved to the gusset plate rather than the weld zone, therefore the gusset plate makes the joint in the enhanced model more ductile than the joint in the base model. Life cycles to failure for the enhanced model are more than life cycles to failure in the base model. It is therefore found that this has useful applications in the steel construction industry.

The fatigue life of a friction stir welded 19501 aluminium alloy T-joint

2018 ◽  
Vol 27 (1-2) ◽  
Author(s):  
Prakash Chandra Gope ◽  
Harshit Kumar ◽  
Himanshu Purohit ◽  
Manish Dayal
Keyword(s):  
Aluminium Alloy ◽  
Weld Zone ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Test Results ◽  
Element Analysis ◽  
Friction Stir ◽  
Fracture Surfaces ◽  
Proposed Model ◽  
Stress Ratios

AbstractFriction stir welding (FSW) is a solid-state joining which reduces the structural weight significantly and hence it has received worldwide attention for the joining of aluminium alloys. In this paper, fatigue tests and finite element analysis were employed to study the mechanical and fatigue properties of a friction stir welded T-joint of 19501 aluminium alloy. An LS-2 FSW machine with 100 kN capacity was used to fabricate the T and butt joints. The tensile properties of the friction stir welded joint show that there is a marginal reduction of about 5% in strength and ductility as compared to an un-welded 19501 aluminium alloy. S-N test results of theT-joint specimen at two stress ratios of 0 and −1 showed that there was a reduction of 15% in the fatigue strength due to the change of stress ratio from 0 to −1. The effect of mean stress can be well approximated using Goodman’s criterion as compared to Gerber’s or Soderberg’s criteria. The predicted fatigue lives from the proposed model using the Palmgren-Miner rule (PMR) were found to be within reasonable accuracy. Micrographs shown for the fracture surfaces of the retreating side, mid-weld zone and the advancing side of the T-joint indicate that fracture surfaces are a mixture of dimple and cleavage features.

Faktor – Faktor Yang Mempengaruhi Minat Berwirausaha Mahasiswa Program Studi Manajemen Fakultas Ekonomi Universitas Flores

Analisis ◽  
2020 ◽  
Vol 19 (1) ◽  
pp. 76-84
Author(s):  
Nasarius Aban ◽  
Gabriel Tanusi
Keyword(s):  
Emotional Intelligence ◽  
Regression Analysis ◽  
Family Environment ◽  
Linear Regression Analysis ◽  
Simple Random Sampling ◽  
Coefficient Of Determination ◽  
Test Results ◽  
Study Program ◽  
Management Study ◽  
The University

This study aims to determine the effect of emotional intelligence, independent attitude and family environment on the interest in entrepreneurship at the University of Flores Management Faculty of Economics. This research is an associative research. The population in this study were students of the Management Study Program of the Faculty of Economics of the University of Flores in the class of 2015-2016 who had passed the entrepreneurship courses of 170 people. Samples taken in this study were 105 respondents, with sampling techniques using simple random sampling. Data collection using questionnaires and interviews, while data analysis was performed using multiple linear regression analysis. The results of multiple regression analysis are Y = 1.060 + 0.594X1 + 0.114X2 + 0.421X3 + e. The coefficient of determination R2 for the variables X1, X2, X3 is 0.675, which means that entrepreneurial interest can be influenced by emotional intelligence, independent attitude and family environment by 67.50% and the remaining 32.50% is influenced by other factors including factors of education, skills, motivation and others. F test results show the value of Fcount> Ftable (28.442> 2.69) with a significant level of 0.000 <0.05 meaning that there is a positive and significant influence between emotional intelligence, independent attitude and family environment together on the entrepreneurial interest of the Faculty of Management Study Program Students The economy. Partial test results (t) show 1) Emotional intelligence factors have a positive and significant effect on entrepreneurial interest 2) Family environment factors have a positive and significant effect on entrepreneurial interest 3) Independent attitude factor has no positive and significant effect on entrepreneurial interest.

Promoting positive washforward through personalised test feedback and other benefits: Piloting a computer-based testing system

2020 ◽  
Vol 10 (1) ◽  
pp. 235-244
Author(s):  
Elena A. M. Gandini ◽  
Tania Horák
Keyword(s):  
Foreign Language ◽  
Testing System ◽  
Test Results ◽  
Test Feedback ◽  
Teachers And Students ◽  
Computer Based ◽  
Computer Based Testing ◽  
The University ◽  
Future Learning ◽  
Personalised Feedback

AbstractThis contribution reports on the developing and piloting of a computer-based version of the test of English as a foreign language produced by the University of Central Lancashire (UCLan), where it is currently used for the admission of international students and the subsequent evaluation of their language progress. Among other benefits, computer-based testing allows for better and individualised feedback to both teachers and students, and it can provide a more authentic test experience in light of the current digital shift that UK universities are undergoing. In particular, the qualitative improvement in the feedback available for test-takers and teachers was for us a crucial factor. Providing students with personalised feedback, that is, directly linked to their performance, has positive washforward, because it means we can guide their future learning, highlighting the areas they need to work on to improve their language skills and giving them suggestions on how to succeed in academia. Furthermore, explaining the meaning of test results in detail improves transparency and ultimately washback, as teachers can use the more accessible marking criteria, together with information on how their students performed, to review plans and schemes of work for subsequent courses.

Finite Element Analysis of Reinforced Concrete Beams with Exterior FRP Shell

2011 ◽  
Vol 243-249 ◽  
pp. 1461-1465
Author(s):  
Chuan Min Zhang ◽  
Chao He Chen ◽  
Ye Fan Chen
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Test Results ◽  
Contact Interface ◽  
Accurate Calculation ◽  
Element Analysis

The paper makes an analysis of the reinforced concrete beams with exterior FRP Shell in Finite Element, and compares it with the test results. The results show that, by means of this model, mechanical properties of reinforced concrete beams with exterior FRP shell can be predicted better. However, the larger the load, the larger deviation between calculated values and test values. Hence, if more accurate calculation is required, issues of contact interface between the reinforced concrete beams and the FRP shell should be taken into consideration.

Experimental and theoretical study of sandwich composites with Z-pins under quasi-static compression loading

2021 ◽  
pp. 136943322110073
Author(s):  
Erdem Selver ◽  
Gaye Kaya ◽  
Hussein Dalfi
Keyword(s):  
Vinyl Ester ◽  
Failure Modes ◽  
Critical Role ◽  
Sandwich Composites ◽  
Test Results ◽  
Compressive Properties ◽  
Element Analysis ◽  
Static Compression ◽  
Quasi Static Compression ◽  
Good Agreement

This study aims to enhance the compressive properties of sandwich composites containing extruded polystyrene (XPS) foam core and glass or carbon face materials by using carbon/vinyl ester and glass/vinyl ester composite Z-pins. The composite pins were inserted into foam cores at two different densities (15 and 30 mm). Compression test results showed that compressive strength, modulus and loads of the sandwich composites significantly increased after using composite Z-pins. Sandwich composites with 15 mm pin densities exhibited higher compressive properties than that of 30 mm pin densities. The pin type played a critical role whilst carbon pin reinforced sandwich composites had higher compressive properties compared to glass pin reinforced sandwich composites. Finite element analysis (FE) using Abaqus software has been established in this study to verify the experimental results. Experimental and numerical results based on the capabilities of the sandwich composites to capture the mechanical behaviour and the damage failure modes were conducted and showed a good agreement between them.

scholarly journals The small strain stiffness from bender elements tests for clayey soils

2018 ◽  
Vol 50 (4) ◽  
pp. 353-371
Author(s):  
Katarzyna Markowska-Lech ◽  
Wojciech Sas ◽  
Mariusz Lech ◽  
Katarzyna Gabryś ◽  
Alojzy Szymański
Keyword(s):  
Field Tests ◽  
Small Strain ◽  
Test Results ◽  
Bender Elements ◽  
Element Analysis ◽  
Factors Affecting ◽  
Small Strain Stiffness ◽  
Seismic Wave Velocities ◽  
Case Basis ◽  
Hardening Soil Model

Abstract The shear modulus of soils at small strain (G0) is one of the input parameters in a finite element analysis with the hardening soil model with small strain stiffness, required in the advanced numerical analyses of geotechnical engineering problems. The small strain stiffness can be determined based on the seismic wave velocities measured in the laboratory and field tests, but the interpretation of test results is still under discussion because of many different factors affecting the measurements of the wave travel time. The recommendations and proposed solutions found in the literature are helpful as a guide, but ought to be adopted with a certain measure of care and caution on a case-by-case basis. The equipment, procedures, tests results and interpretation analyses of bender elements (BE) tests performed on natural overconsolidated cohesive soils are presented.

Finite Element Analysis of Rail-End Bolt Hole and Fillet Stress on Bolted Rail Joints

2017 ◽  
Vol 2607 (1) ◽  
pp. 33-42 ◽  
Author(s):  
Kaijun Zhu ◽  
Yu Qian ◽  
J. Riley Edwards ◽  
Bassem O. Andrawes
Keyword(s):  
Finite Element ◽  
Vertical Displacement ◽  
Rail Transit ◽  
Rail Transportation ◽  
Element Analysis ◽  
Transit System ◽  
Transit Systems ◽  
Service Failures ◽  
The University ◽  
Continuously Welded Rail

A rail joint typically is one of the weakest elements of a track superstructure, primarily because of discontinuities in its geometric and mechanical properties and the high-impact loads induced by these discontinuities. The development of continuously welded rail has significantly reduced the number of rail joints, but many bolted joints remain installed in rail transit systems. Because of the unique loading environment of a rail transit system (especially high-frequency, high-repetition loads), defects related to bolted rail joints (e.g., joint bar failures, bolt hole cracks, and cracks in the upper fillet) continue to cause service failures and can pose derailment risks. Recent research in the Rail Transportation and Engineering Center at the University of Illinois at Urbana–Champaign has focused on investigating crack initiation in the bolt hole and fillet areas of bolted rail joints. Stress distribution was investigated at the rail-end bolt hole and upper fillet areas of standard, longer, and thicker joint bars under static loading conditions. Numerical simulations were organized into a comprehensive parametric analysis performed with finite element modeling. Preliminary results indicated that the longer joint bar performed similarly to the standard joint bar but the thicker joint bar reduced rail vertical displacement and rail upper fillet stresses compared with the standard joint bar. However, the thicker joint bar also may generate higher stresses at the rail-end bolt hole. Additionally, joint bar performance was dependent on the rail profile and bolt hole location.

Parametric Evaluation on the Response of Damaged Simple Supported Structure Under Transit Mass

2017 ◽  
Author(s):  
Shakti P. Jena ◽  
Dayal R. Parhi ◽  
B. Subbaratnam
Keyword(s):  
Finite Element Analysis ◽  
Integral Method ◽  
Critical Speed ◽  
Crack Depth ◽  
Element Analysis ◽  
Simply Supported ◽  
Crack Location ◽  
Integral Converge ◽  
Duhamel Integral ◽  
Ansys Workbench

In the present article, the responses of a double cracked simply supported beam have been investigated. The responses of the structure are determined using Duhamel integral method numerically and validated with finite element analysis (FEA) using ANSYS WORKBENCH 2015 along with experimental verifications. The mass is moving on the structure in terms of critical speed of the structure. The normalized deflections of the structure at different damaged configurations are calculated. The influences of speed, mass, crack depth and crack location on the structures response are investigated. It is observed that the results obtained from Duhamel integral converge well with FEA and experimental verifications.

The value of crowdsourcing in apparel and fashion retail buying

2019 ◽  
Author(s):  
◽  
Omid Kamran-Disfani
Keyword(s):  
Demand Uncertainty ◽  
Subjective Assessment ◽  
Life Cycles ◽  
University Of Missouri ◽  
Product Categories ◽  
Fashion Products ◽  
Fashion Retail ◽  
Short Product ◽  
The University ◽  
Future Demand

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Apparel and fashion retail buyers are responsible for selecting and ordering products, on behalf of the retailer, to be sold to retailers' end-consumers. Compared to their counterparts in other retailing sectors, fashion buyers face unique challenges such as high demand uncertainty and volatility, seasonality, frequent changes in fashion trends, and short product life cycles. As previous trends rarely provide useful information for predicting future sales of trendy products, fashion buyers make a subjective assessment of products' future demand by relying on their intuition and perceived expertise. Industry reports show that fashion buyers' predictions are often far from the demand that is later realized causing loss of profits for retailers. In this dissertation. I argue that retailers can benefit from the Wisdom of the Crowd (WOC) in predicting future sales of fashion products. It is suggested that lay customers as a group can provide more accurate prediction of future demand of fashion products than individual fashion buyers. An empirical study is conducted to test this proposition involving two groups: professional fashion buyers (N=60) and lay customers (N=397). Customers predicted future sales of products in all six product categories that were used in the study. The prediction error, measured by MAPE, was reduced between 12 and 73 percent. The implication of these findings for retailers are discussed, and directions for implementing crowdsourcing in fashion buying to improve prediction accuracy are provided.

Automated Approaches Determine Solids Content in Drilling and Completions Fluids

2021 ◽  
Vol 73 (11) ◽  
pp. 51-52
Author(s):  
Chris Carpenter
Keyword(s):  
Elevated Temperatures ◽  
Drilling Fluid ◽  
Technical Conference ◽  
Drilling Fluids ◽  
Test Results ◽  
University Of Texas ◽  
Safety Issues ◽  
Recommended Practices ◽  
Solids Content ◽  
The University

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 201368, “Automated Solids-Content Determination in Drilling and Completions Fluids,” by Sercan Gul, SPE, Ali Karimi Vajargah, and Eric van Oort, SPE, The University of Texas at Austin, et al., prepared for the 2020 SPE Annual Technical Conference and Exhibition, originally scheduled to be held in Denver, 5–7 October. The paper has not been peer reviewed. Monitoring of low- and high-gravity-solids (LGS and HGS) content and maintaining these at ideal levels is essential for optimal drilling fluid performance, efficient hole cleaning and equivalent-circulating-density management, and prevention of failures of surface and downhole equipment during drilling. LGS and HGS monitoring in the field is currently accomplished using the API retort-kit measurement, which has certain drawbacks and is difficult to automate. In the complete paper, two new approaches are investigated to automate the LGS and HGS content measurements of drilling fluids, which potentially can replace the retort test. Introduction The conventional way to characterize LGS and HGS in the field is by using a retort-kit measurement specified in API Recommended Practices 13B-1 and 13B-2. The longevity of these tests is testament to the effectiveness of the API standards and the tests themselves in providing useful and practical field guidance. Despite their evident success, however, various downsides exist in current solids-content-testing methods. Retort-kit measurements present the following issues: - Difficulty in obtaining accurate and repeatable test results - Safety issues associated with laboratory testing at elevated temperatures (over 930°F) - Interpretive bias issues associated with test results, including the potential for deliberate manipulation of these results - Difficulty in automating the retort test for improved efficiency and safety The authors’ opinion is that automating antiquated API test protocols is not a useful practice. They write that a clean-slate approach would be better, in which a determination is made whether solids-content information can be provided in a novel and meaningful way using methods that deviate from standard API recommended practices. In the complete paper, the authors investigate a machine-learning (ML) and data-analytics method for this purpose in combination with a novel inline X-ray fluorescence (XRF) measurement method.

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