A new performance based design approach for moment resisting frames

2012 ◽  
Vol 39 (4) ◽  
pp. 473-483 ◽  
Author(s):  
Mark Grigorian ◽  
Carl E. Grigorian
Keyword(s):  
Design Method ◽  
Seismic Loading ◽  
Performance Based Design ◽  
Equilibrium Conditions ◽  
Future Behavior ◽  
Straight Line ◽  
Before And After ◽  
Moment Resisting ◽  
Strength And Stiffness ◽  
Constituent Elements

This paper proposes a simple, relatively new elastic–plastic design method for earthquake resisting frames that enables the engineer to directly control the essential aspects of the future behavior of certain structural forms, through basic statics and imposition of predetermined modes of behavior. The method is particularly applicable to the preliminary design of low to mid-rise buildings where the fundamental period of vibrations dominates the response of the system to seismic loading. The focus of this paper is directed towards simplified but accurate manual design rather than sophisticated structural analysis. The premise of the proposed solution is that the constituent elements of the system can be selected in such a way as to cause both the elastic as well as the plastic drift functions to follow linearly varying straight line profiles during all phases of loading. Frameworks designed by this method act not only as structures of uniform response (UR), i.e., uniform strength and stiffness, where the demand/capacity ratios of its members remain the same, both before and after formation of plastic hinges, but they also result in unique solutions, satisfying the prescribed yield criteria, the boundary support, as well as the of static equilibrium conditions.

scholarly journals Response modification factors for dual moment-resisting frames with vertical links: Multilevel approach

2021 ◽  
pp. 136943322110262
Author(s):  
Vahid Mohsenian ◽  
Nima Gharaei-Moghaddam ◽  
Iman Hajirasouliha
Keyword(s):  
Demand Response ◽  
Earthquake Hazard ◽  
Performance Based Design ◽  
Response Modification Factor ◽  
Seismic Reliability ◽  
Moment Resisting Frames ◽  
Before And After ◽  
Moment Resisting ◽  
And Performance ◽  
Hazard Level

Despite the growing applications of the performance-based design concepts for seismic design of structures, the response modification factors for structural systems proposed by the current design codes and standards do not generally consider different hazard and performance levels. Therefore, these factors are not directly applicable for performance-based design purposes. As a step to address this shortcoming, the present study aims to propose multilevel response modification factors for multistory dual moment-resisting frames equipped with eccentric braces and vertical links corresponding to different seismicity levels and performance targets. The concept of demand and capacity response modification factors is introduced, and these parameters are calculated for moment-resisting frame structures with 3-, 5-, and 7-stories before and after the addition of vertical steel shear links. It is shown that the calculated capacity response modification factors for the dual frames equipped with vertical links are generally higher than the demand response modification factors proposed by the design code for such systems under the design basis earthquake hazard level. This indicates the efficiency of the eccentric braces with the vertical links in improving the seismic reliability and performance of the moment-resisting steel frames. Based on the results of this study, the demand response modification factor for the studied dual lateral load-resisting system is calculated to be in the range of 7–10.

scholarly journals Comparative Study of Direct Displacement Based and Forced Based Design Method for RC- Frame with Shear Wall

10.29007/lft5 ◽  
2018 ◽  
Author(s):  
Bijal Chaudhri ◽  
Dipali Patel
Keyword(s):  
Seismic Design ◽  
Design Method ◽  
Shear Wall ◽  
Performance Based Design ◽  
Rc Frame ◽  
Base Shear ◽  
Global Parameter ◽  
Direct Displacement Based Design ◽  
Moment Resisting ◽  
Displacement Based

The Seismic design of structure has conventionally been force based. Displacement is the major factor for the damage rather than force. The alternative procedure for seismic design, which becomes more popular, is performance based design method. Displacement is global parameter of performance based design method. Direct displacement based design method has been used for seismic design of structure. The paper attempts to design moment resisting RC-frame using Displacement based design method and Forced based design method. 15-storey building with shear wall has been taken for parametric study. The parameter like base shear and lateral load distribution are taken for the study. It is observed that base shear of RC building calculated by DDBD is less compared to FBD.

Automatic Tread Gaging Machine

1979 ◽  
Vol 7 (1) ◽  
pp. 31-39
Author(s):  
G. S. Ludwig ◽  
F. C. Brenner
Keyword(s):  
Experimental Tests ◽  
Automatic Machine ◽  
Wear Rates ◽  
Handling Device ◽  
Straight Line ◽  
Component Systems ◽  
Before And After ◽  
Good Repeatability ◽  
The Difference ◽  
Straight Lines

Abstract An automatic tread gaging machine has been developed. It consists of three component systems: (1) a laser gaging head, (2) a tire handling device, and (3) a computer that controls the movement of the tire handling machine, processes the data, and computes the least-squares straight line from which a wear rate may be estimated. Experimental tests show that the machine has good repeatability. In comparisons with measurements obtained by a hand gage, the automatic machine gives smaller average groove depths. The difference before and after a period of wear for both methods of measurement are the same. Wear rates estimated from the slopes of straight lines fitted to both sets of data are not significantly different.

Structural Behaviour of Blind Bolted Connection to Concrete-Filled Steel Tubular Columns

2010 ◽  
Vol 163-167 ◽  
pp. 591-595
Author(s):  
Jing Feng Wang ◽  
Xin Yi Chen ◽  
Lin Hai Han
Keyword(s):  
Analysis Model ◽  
Bolted Connections ◽  
Structural Behaviour ◽  
Tubular Columns ◽  
End Plate ◽  
Moment Resisting ◽  
Strength And Stiffness ◽  
Plate Connections ◽  
The Moment ◽  
Plate Connection

This paper studies structural behaviour of the blind bolted connections to concrete-filled steel tubular columns by a serial of experimental programs, which conducted involving eight sub-assemblages of cruciform beam-to-column joints subjected to monotonic loading and cyclic loading. The moment-rotation hysteretic relationships and failure models of the end plate connections have been measured and analyzed. A simplified analysis model for the blind bolted connections is proposed based on the component method. It is concluded that the blind bolted end plate connection has reasonable strength and stiffness, whilst the rotation capacity of the connection satisfies the ductility requirements for earthquake-resistance in most aseismic regions. This typed joint has excellent seismic performance, so it can be used in the moment-resisting composite frame.

Earthquake Performance Analysis of Steel Structures with A3 Plan Irregularities

2021 ◽  
Vol 10 (12) ◽  
pp. 174-179
Author(s):  
Özlem Çavdar
Keyword(s):  
Earthquake Engineering ◽  
Design Method ◽  
Steel Structures ◽  
Nonlinear Static Analysis ◽  
Seismic Performance Evaluation ◽  
Moment Resisting Frame ◽  
Earthquake Effect ◽  
Steel Building ◽  
Moment Resisting ◽  
Earthquake Performance

In earthquake engineering, a performance-based design method is used to determine the level of the expected performance of the structures under the earthquake effect. The level of performance is related to the damage situation that could be occurred in the structure after the earthquake. In the performance-based structural design, it is predicted that more than one damage levels emerge under one certain earthquake effect. In this study, the seismic behavior of steel structures with plan irregularities in the Turkey Building Earthquake Code in the 2018 (TBEC-2018) is investigated by the nonlinear static analysis methods. The selected steel structures are located in İzmir, Turkey. The Turkey Earthquake Code in 2018 is considered for assessing seismic performance evaluation of the selected moment-resisting frame steel building. Four different A3 type irregularity was investigated. The steel building with no irregularity in its plan. was selected as the structure of the reference. The performance goals of the five different steel structures are evaluated by applying the pushover and procedures of the TBEC-2018. The steel structures were compared by obtaining pushover curves for both the X and Y directions. The results show that the effects of A3 type irregularity should be not considered in design and buildings without irregularities are safer.

scholarly journals Impact of a Vibrotactile Belt on Emotionally Challenging Everyday Situations of the Blind

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7384
Author(s):  
Charlotte Brandebusemeyer ◽  
Anna Ricarda Luther ◽  
Sabine U. König ◽  
Peter König ◽  
Silke M. Kärcher
Keyword(s):  
Emotional Impact ◽  
Vibrotactile Stimulation ◽  
Angular Rotation ◽  
Straight Line ◽  
Before And After ◽  
Fixed Reference ◽  
Behavioural Experiments ◽  
Triangle Completion ◽  
Subjective Discomfort ◽  
Magnetic North

Spatial orientation and navigation depend primarily on vision. Blind people lack this critical source of information. To facilitate wayfinding and to increase the feeling of safety for these people, the “feelSpace belt” was developed. The belt signals magnetic north as a fixed reference frame via vibrotactile stimulation. This study investigates the effect of the belt on typical orientation and navigation tasks and evaluates the emotional impact. Eleven blind subjects wore the belt daily for seven weeks. Before, during and after the study period, they filled in questionnaires to document their experiences. A small sub-group of the subjects took part in behavioural experiments before and after four weeks of training, i.e., a straight-line walking task to evaluate the belt’s effect on keeping a straight heading, an angular rotation task to examine effects on egocentric orientation, and a triangle completion navigation task to test the ability to take shortcuts. The belt reduced subjective discomfort and increased confidence during navigation. Additionally, the participants felt safer wearing the belt in various outdoor situations. Furthermore, the behavioural tasks point towards an intuitive comprehension of the belt. Altogether, the blind participants benefited from the vibrotactile belt as an assistive technology in challenging everyday situations.

scholarly journals The configuration of the Pontus Euxinus in Ptolemy's Geography

2020 ◽  
Vol 11 (1) ◽  
pp. 31-51
Author(s):  
Dmitry A. Shcheglov
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
North East ◽  
The Earth ◽  
Open Sea ◽  
Straight Line ◽  
Key Points ◽  
Similarities And Differences ◽  
Types Of Information ◽  
Constituent Elements

Abstract. This article aims to explain how Ptolemy could have constructed a map of the Pontus Euxinus (Black Sea), as described in his Geography, under the assumption that his sources were similar to those that have come down to us. The method employed is based on the comparison of Ptolemy's data with corresponding information from other ancient sources, revealing the most conspicuous similarities and differences between them. Three types of information are considered as possible “constituent elements” of Ptolemy's map: latitudes, coastline lengths, and straight-line distances. It is argued that the latitudes Ptolemy used for the key points determining the overall shape of the Pontus (Byzantium, Trapezus, the mouth of the Borysthenes and the Cimmerian Bosporus, the mouth of the Tanais, etc.) were most likely inherited from earlier geographers (Eratosthenes, Hipparchus, and Marinus). In exactly the same way, Ptolemy's data on the circumference of the Pontus and the length of the coastal stretches between the key points (from the Thracian Bosporus to Cape Karambis, Sinope, Trapezus, and the mouth of the Phasis, etc.) closely correlate with the corresponding estimates reported by other geographers (Eratosthenes, Artemidorus, Strabo, Pliny, Arrian, and Pseudo-Arrian), which implies that Ptolemy drew on similar coastline length information. The shortening of Ptolemy's west coast of the Pontus (from the Thracian Bosporus to the mouth of the Borysthenes) relative to the corresponding distances reported by other sources is explained by his underestimation of the circumference of the Earth. The lengthening of Ptolemy's north-east Pontus coast (from the Cimmerian Bosporus to the mouth of the Phasis) can, in part, be accounted for by his attempt to incorporate the straight-line distances across the open sea reported by Pliny. Overall, Ptolemy's configuration of the Black Sea can be satisfactorily explained as a result of fitting contradictory pieces of information together that were inherited from earlier geographical traditions.

scholarly journals Peningkatan Soft Skills Pribadi Konselor Mahasiswa BKI Melalui kegaitan Career Development Program (CDP)

2018 ◽  
Vol 5 (2) ◽  
pp. 171
Author(s):  
Triyono Triyono ◽  
Syakirin Al-Ghozaly ◽  
Vera Imanti
Keyword(s):  
Career Development ◽  
Soft Skills ◽  
Design Method ◽  
Development Program ◽  
Guidance And Counseling ◽  
Test Analysis ◽  
Before And After ◽  
Post Test ◽  
Career Development Program ◽  
Personal Competencies

Soft skills are a set of abilities related to adjustments to oneself, others, and the environment. The counselor's personal soft skills mean the abilities or personal competencies possessed by a counselor. This study aims to determine how much the Career Development Program (CDP) influences in developing the counselor's personal soft skills of BKI students. The design of this research is quantitative experimental, using the pre-experimental design method with the type of pre-test and post-test one group design. The population of this study were the students of Islamic Guidance and Counseling (BKI) IAIN Surakarta 2015/2016, 2016/2017, and 2017/2018 academic years. The sample in this study were 90 students by taken in 3 classes in each academic year, through stratified cluster random sampling. Measurement of the counselor's personal soft skills using EPPS psychological instruments. The research results of the counselor’s personal soft skills of BKI students before and after being given Career Development Program (CDP) training, both in the second semester, 4th semester and 6th semester students groups showed significant differences. The results of paired t-test analysis obtained the pretest and posttest values with sig values = 0.000 <0.05. This means that the Career Development Program (CDP) has a significant effect on improving the counselor's personal soft skills of BKI students. The Career Development Program (CDP) is a model for the development and improvement of personal counselor’s soft skills that are effective for the students of BKI IAIN Surakarta

scholarly journals Curable Area Substantiation of Self-Healing in Concrete Using Neutral Axis

2019 ◽  
Vol 9 (8) ◽  
pp. 1537 ◽  
Author(s):  
Choonghyun Kang ◽  
Taewan Kim
Keyword(s):  
Neutral Axis ◽  
The Self ◽  
Strain Gauges ◽  
Self Healing ◽  
Distinct Area ◽  
Before And After ◽  
Strength And Stiffness ◽  
Underlying Mechanisms ◽  
Healing Assessment ◽  
Physical Recovery

The self-healing nature of concrete has been proved in many studies using various methods. However, the underlying mechanisms and the distinct area of self-healing have not been identified in detail. This study focuses on the limits of the area of self-healing. A bending specimen with a notch is used herein, and its flexural strength and stiffness before and after healing are compared and used for self-healing assessment. In addition, the neutral axis of the specimen was measured using successive strain gauges attached to the crack propagation part. Although the strength and stiffness of the concrete recovered after self-healing, the change in the location of the neutral axis before and after healing was insignificant, which indicates that physical recovery did not occur for once-opened crack areas.

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