• Title, Summary, Keyword: shear design

Search Result 2,784, Processing Time 0.054 seconds

Optimal Design of Tall Residential Building with RC Shear Wall and with Rectangular Layout

  • Jinjie, Men;Qingxuan, Shi;Zhijian, He
    • International Journal of High-Rise Buildings
    • /
    • v.3 no.4
    • /
    • pp.285-296
    • /
    • 2014
  • The objective of optimization is to present a design process that minimizes the total material consumption while satisfying current codes and specifications. In the research an optimization formulation for RC shear wall structures is proposed. And based on conceptual design methodology, an optimization process is investigated. Then optimal design techniques and specific explanations are introduced for residential buildings with shear wall structure, especially for that with a rectangular layout. An example of 30-story building is presented to illustrate the effectiveness of the proposed optimal design process. Furthermore, the influence of aspect ratio on the concrete consumption and the steel consumption of the superstructure are analyzed for this typical RC shear wall structure; and their relations are obtained by regressive analysis. Finally, the optimal material consumption is suggested for the residential building with RC shear wall structure and with rectangular layout. The relation and the data suggested can be used for guiding the design of similar RC shear wall structures.

An Experimental Study on the Block Shear Rupture of Angle Tension Members (인장력을 받는 ㄱ형강의 블록전단 파단에 관한 실험적 연구)

  • Kim, Bo Young;Lee, Kyu Kwong;Choi, Mun Sik
    • Journal of Korean Society of Steel Construction
    • /
    • v.10 no.4
    • /
    • pp.721-730
    • /
    • 1998
  • In this paper, an experimental study have been many studies on the joints of steel structure, for it has great influences on the safety of structures. Research on block shear rupture of the joint receiving pure tension have been done in foreign countries, but not in Korea. This study focuses on the propriety of block shear design code, according to limited state design criteria of steel structures recently established in Korea, by an experiment on the joint of angle tension members. The methods of this study were to compare other study results on block shear rupture mode and ultimate capacity, and to evaluate the propriety of the criteria design code. The result is that tension yield shear ruptures and shear yield tension ruptures happened at the joint, and the experimental rupture load was 15% higher than the capacity entered in the criteria design code. We conclude that it is necessary to revaluate the block shear design code presented by many studies on the limited state design criteria of steel structures.

  • PDF

Combined Design Method for Shear and Torsional Moment (전단과 비틀림모멘트 설계의 조합)

  • Min, Chang-Shik
    • Journal of the Korea Concrete Institute
    • /
    • v.23 no.1
    • /
    • pp.57-65
    • /
    • 2011
  • Both shear and torsional moments apply shear stresses on cross-section of a member, which need to be considered in the design. But in the current Korean Building Code, the design equations for shear and torsional moments are expressed in terms of the sectional strength with different units, causing figures to be drawn separately in two axes. If the design equations are expressed in terms of stresses, then the stresses of shear and torsional moments can be added, allowing figures to be drawn in one axis for easy recognition of the design procedure and the final design results. Moreover, the current code's design equations for shear and torsional moments are considered separately with the intention of summing the area of stirrups with respect to unit length for shear moment ($A_{\upsilon}/s$) and torsional moment ($2A_t/s$). Since the size or type of vertical stirrups are predetermined in the design process, the design equations are expressed in terms of the spacing of stirrups rather than the $A_{\upsilon}/s$ and $2A_t/s$ terms, clarifying various design steps and a design process.

Design Shear Force Reduction Factor of Upper Structure in Seismic Base-isolated System Considering Response Acceleration Decrement Effect (면진구조의 응답가속도 감소효과를 고려한 상부구조의 설계전단력 저감계수)

  • Chen, Hao;Oh, Sang-Hoon
    • Journal of the Architectural Institute of Korea Structure & Construction
    • /
    • v.35 no.7
    • /
    • pp.165-170
    • /
    • 2019
  • The structural damage caused by earthquake to the upper structure of seismic base-isolated system can be suppressed effectively because it is designed to concentrate the input energy on the seismic isolation floor. Further, the response acceleration of seismic base-isolated system can be greatly reduced compared to the seismic structure because of the long period, which means that the design shear force of the seismic base-isolated system can be reduced appropriately. However, when the design shear force is determined to be reduced, the design stiffness will decrease, and the response acceleration will increase oppositely. Therefore, for finding the extent to which the design shear force of the upper structure can be reduced, this paper considered the seismic base-isolated structure as the analytical model and proposed the design shear force reduction factor of the base-isolated structure through the dynamic response analysis, while considering the decrement effect of response acceleration. The research result shows that the response acceleration of the isolated the upper structure can be reduced by 50%~70% of the seismic structure under the same design conditions, and the design shear force can be reduced by up to 40%. By increasing the design stiffness over to 1.8 times of the original design value, the design shear force can be reduced to the same extent as the response acceleration can be reduced compared to the seismic structure.

FEM Analysis of RC Deep Beam Depending on Shear-Span Ratio

  • Lee, Yongtaeg;Kim, Seongeun;Kim, Seunghun
    • Architectural research
    • /
    • v.19 no.4
    • /
    • pp.117-124
    • /
    • 2017
  • In this research, we carried out finite element analysis depends on the variations such as the strength of the main bar, concrete, shear-span ratio(a/d) and existence of shear reinforcing bar. Throughout the results of FEM analysis, we were able to figure out how each variation can effect on shear performance. As the strength of concrete increased, the maximum shear force enhancement effect of each specimen was evaluated. As a result, the shear strengthening effect was 51~97% for shear reinforced specimens, and 26~44% for non-shear reinforced specimens. As the yield strength of reinforcing bars increases, the shear reinforcement effect of the specimen the specimens without shear reinforcement were 3%~6% higher than those with shear reinforcement. Theoretical and analytical values were compared using the design equations obtained from the CEB code. Theoretical and analytical values were compared using the design equations obtained from the CEB code. As a result, the error rate was the highest at 3.64 in the S1.0-C0 series and the lowest at 1.46 in the S1.7-C1 series. Therefore, the design equation of the CEB code is estimated to underestimate the actual shear strength of deep beams that are not subjected to shear reinforcement.

Performance based evaluation of RC coupled shear wall system with steel coupling beam

  • Bengar, Habib Akbarzadeh;Aski, Roja Mohammadalipour
    • Steel and Composite Structures
    • /
    • v.20 no.2
    • /
    • pp.337-355
    • /
    • 2016
  • Steel coupling beam in reinforced concrete (RC) coupled shear wall system is a proper substitute for deep concrete coupling beam. Previous studies have shown that RC coupled walls with steel or concrete coupling beam designed with strength-based design approach, may not guarantee a ductile behavior of a coupled shear wall system. Therefore, seismic performance evaluation of RC coupled shear wall with steel or concrete coupling beam designed based on a strength-based design approach is essential. In this paper first, buildings with 7, 14 and 21 stories containing RC coupled shear wall system with concrete and steel coupling beams were designed with strength-based design approach, then performance level of these buildings were evaluated under two spectrum; Design Basis Earthquake (DBE) and Maximum Considered Earthquake (MCE). The performance level of LS and CP of all buildings were satisfied under DBE and MCE respectively. In spite of the steel coupling beam, concrete coupling beam in RC coupled shear wall acts like a fuse under strong ground motion.

Shear Behavior of Pyramidal Shear Connectors (피라미드형 전단연결재의 전단거동)

  • Lee, Kyeong-Dong;Han, Sang-Ho
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.4 no.2
    • /
    • pp.131-137
    • /
    • 2000
  • In order to evaluate the design shear strength of composite slabs with truss-shaped shear connectors(TSC), a series of push-out tests on several types of specimens was carried out. The test results for the two parameters of bearing area and solid angle of the connector were compared to obtain the design shear force of the truss-shaped connectors. The results obtained from this study are as follows: (1) The slip-coefficients of TSC ranges from 0.87 to 3.12(${\times}10^6kgf/cm$). (2) The slip stiffness and the shear strength of TSC with $60.6cm^2$ bearing area are greater than those with $14.6cm^2$. (3) For estimating the allowable shear force of TSC, a design equation that is based on the bearing strength of the connector is suggested. (4) The mean safety factors of the critical force and the ultimate force are 2.38 and 4.62. respectively.

  • PDF

Evaluation and Improvement of Deformation Capacities of Shear Walls Using Displacement-Based Seismic Design

  • Oh, Young-Hun;Han, Sang-Whan;Choi, Yeoh-Soo
    • International Journal of Concrete Structures and Materials
    • /
    • v.18 no.1E
    • /
    • pp.55-61
    • /
    • 2006
  • RC shear walls are frequently used as lateral force-resisting system in building construction because they have sufficient stiffness and strength against damage and collapse. If RC shear walls are properly designed and proportioned, these walls can also behave as ductile flexural members like cantilevered beams. To achieve this goal, the designer should provide adequate strength and deformation capacity of shear walls corresponding to the anticipated deformation level. In this study, the level of demands for deformation of shear walls was investigated using a displacement-based design approach. Also, deformation capacities of shear walls are evaluated through laboratory tests of shear walls with specific transverse confinement widely used in Korea. Four full-scale wall specimens with different wall boundary details and cross-sections were constructed for the experiment. The displacement-based design approach could be used to determine the deformation demands and capacities depending on the aspect ratio, ratio of wall area to floor plan area, flexural reinforcement ratio, and axial load ratio. Also, the specific boundary detailing for shear wall can be applied to enhance the deformation capacity of the shear wall.

Design Sensitivity Analysis and Topology Optimization of Piezoelectric Crystal Resonators (압전 수정진동자의 설계민감도 해석과 위상 최적설계)

  • Ha Youn-Doh;Cho Seon-Ho;Jung Sang-Sub
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • /
    • pp.335-342
    • /
    • 2005
  • Using higher order Mindlin plates and piezoelectric materials, eigenvalue problems are considered. Since piezoelectric crystal resonators produce a proper amount of electric signal for a thickness-shear frequency, the objective is to decouple the thickness-shear mode from the others. Design variables are the bulk material densities corresponding to the mass of masking plates for electrodes. The design sensitivity expressions for the thickness-shear frequency and mode shape vector are derived using direct differentiation method(DDM). Using the developed design sensitivity analysis (DSA) method, we formulate a topology optimization problem whose objective function is to maximize the thickness-shear component of strain energy density at the thickness-shear mode. Constraints are the allowable volume and area of masking plate. Numerical examples show that the optimal design yields an improved mode shape and thickness-shear energy.

  • PDF

A Study on Optimum Distribution of Story Shear Force Coefficient for Seismic Design of Multi-story Structure

  • Oh, Sang Hoon;Jeon, Jongsoo
    • International Journal of High-Rise Buildings
    • /
    • v.3 no.2
    • /
    • pp.121-145
    • /
    • 2014
  • The story shear force distributions of most seismic design codes generally reflect the influences of higher vibration modes based on the elastic deformations of structures. However, as the seismic design allows for the plastic behavior of a structure, the story shear force distribution shall be effective after it is yielded due to earthquake excitation. Hence this study conducted numerical analyses on the story shear force distributions of most seismic design codes to find out the characteristics of how a structure is damaged between stories. Analysis results show that the more forces are distributed onto high stories, the lower its concentration is and the more energy is absorbed. From the results, this study proposes the optimum story shear force distribution and its calculation formula that make the damages uniformly distributed onto whole stories. Consequently, the story damage distribution from the optimum calculation formula was considerably more stable than existing seismic design codes.