Finite element analysis for the seismic performance of steel frame-tube structures with replaceable shear links

Ming Lian,Hao Zhang,Qianqian Cheng,Mingzhou Su 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.30 No.4

In steel frame-tube structures (SFTSs) the application of flexural beam is not suitable for the beam with span-to-depth ratio lower than five because the plastic hinges at beam-ends can not be developed properly. This can lead to lower ductility and energy dissipation capacity of the SFTS. To address this problem, a replaceable shear link, acting as a ductile fuse at the mid length of deep beams, is proposed. SFTS with replaceable shear links (SFTS-RSLs) dissipate seismic energy through shear deformation of the link. In order to evaluate this proposal, buildings were designed to compare the seismic performance of SFTS-RSLs and SFTSs. Several sub-structures were selected from the design buildings and finite element models (FEMs) were established to study their hysteretic behavior. Static pushover and dynamic analyses were undertaken in comparing seismic performance of the FEMs for each building. The results indicated that the SFTS-RSL and SFTS had similar initial lateral stiffness. Compared with SFTS, SFTS-RSL had lower yield strength and maximum strength, but higher ductility and energy dissipation capacity. During earthquakes, SFTS-RSL had lower interstory drift, maximum base shear force and story shear force compared with the SFTS. Placing a shear link at the beam mid-span did not increase shear lag effects for the structure. The SFTS-RSL concentrates plasticity on the shear link. Other structural components remain elastic during seismic loading. It is expected that the SFTS-RSL will be a reliable dual resistant system. It offers the benefit of being able to repair the structure by replacing damaged shear links after earthquakes.

Parents' Perceptions of their Children with Disabilities, Inclusive Education, and Related Services in Taiwan

Ming-Gon John Lian 대구대학교 2002 Journal of Asia-Pacific Special Education Vol.2 No.1

This study was conducted to investigate 366 parents' perceptions toward their children with disabilities, inclusive education and services in Taiwan. Data revealed that parents generallt had positive perceptions toward their children with disabilities. They indicated that inclusive education and related services were needed but tended to be inadequate. A number of parents' and children' s demographics were found to be related to parentls' perceptions.

Numerical study of the seismic behavior of steel frame-tube structures with bolted web-connected replaceable shear links

Ming Lian,Qianqian Cheng,Hao Zhang,Mingzhou Su 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.35 No.3

Beams of steel frame-tube structures (SFTSs) typically have span-to-depth ratios of less than five. This makes a flexural beam unsuitable for such an application because the plastic hinges at the beam-ends cannot be adequately developed. This leads to lower ductility and energy dissipation capacities of SFTSs. To address this, SFTSs with bolted web-connected replaceable shear links (SFTS-BWSLs) are proposed. In this structural system, a web-connected replaceable shear link with a back-to-back double channel section is placed at the mid-length of the deep beam to act as a ductile fuse. This allows energy from earthquakes to be dissipated through link shear deformation. SFTS and SFTS-BWSL buildings were examined in this study. Several sub-structures were selected from each designed building and finite element models were established to study their respective hysteretic performance. The seismic behavior of each designed building was observed through static and dynamic analyses. The results indicate that the SFTS-BWSL and SFTS have similar initial lateral stiffness and shear leg properties. The SFTS-BWSL had lower strength, but higher ductility and energy dissipation capacities. Compared to the SFTS, the SFTS-BWSL had lower interstory drift, base shear force, and story shear force during earthquakes. This design approach could concentrate plasticity on the shear link while maintaining the residual interstory drift at less than 0.5%. The SFTS-BWSL is a reliable resistant system that can be repaired by replacing shear links damaged due to earthquakes.

홍콩의 특수교육 요구학생을 위한 통합교육의 진전

Ming-Gon John Lian 국립특수교육원 2005 국제세미나 자료집 Vol.2005 No.-

오늘날 홍콩에 있는 학교의 학생들은 다양한 환경에서 학습하고 있다. 여기에는 다양한 수준의 학습 능력과 학습 문제가 포함된다. 과거 10년 동안, 특수교육 요구 학생(SEN)들에 대한 통합교육의 추세는 한결같이 계속 되었다. 제 일선의 전문가들은 장애학생이든 일반학생이든 간에 상관없이 모든 학습자의 개별화된 요구를 충족시키기 위한 필요성을 계속적으로 인식해 왔다. 이 보고서에서는 통합교육의 개념과 이론의 주요배경과 영향력, 통합교육을 성공적으로 실행할 수 있는 홍콩에서의 효과적인 참여와 실제(이것은 정부기관, 학교 교직원, 그 외 참여집단이나 자원봉사집단의 상호보완적이고 협력적인 팀웍에 의해 가능하다) 등에 관련된 정보를 공유하고자 한다. Children in today’s schools in Hong Kong are learning in a diverse environment, including various levels of learning abilities and difficulties. During the past decade, there has been a steady trend of inclusive education for students with special education needs (SEN). The frontline professionals have increased their awareness of the requirements to fulfill individualized needs of all learners, whether disabled or nondisabled. This paper shares information regarding major backgrounds and influence in concept and theory development, and effective engagements and practices in Hong Kongthat can be implemented for better success of inclusive education for all students through the mutual and collaborative teamwork of the governmental agencies, school personnel, and other advocacy and volunteer groups.

Seismic performance of high-strength steel framed-tube structures with bolted web-connected replaceable shear links

Ming Lian,Qianqian Cheng,Binlin Guan,Hao Zhang,Mingzhou Su 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.37 No.3

In steel framed-tube structures (SFTSs), the plastic hinges at beam-ends cannot be adequately improved because of the large cross sections of spandrel beams, which results in the lower ductility and energy dissipation capacities of traditional SFTSs. To address this drawback, high-strength steel fabricated SFTSs with bolted web-connected replaceable shear links (HSFTS-SLs) have been proposed. In this system, shear links use conventional steel and are placed in the middle of the deep spandrel beams to act as energy dissipative components. In this study, 2/3-scaled HSFTS-SL specimens were fabricated, and cyclic loading tests were carried out to study the seismic performance of both specimens. The finite element models (FEMs) of the two specimens were established and the numerical results were compared with the test results. The results showed that the specimens had good ductility and energy dissipation capacities due to the reliable deformation capacities. The specimens presented the expected failure modes. Using a shorter shear link can provide a higher load-carrying capacity and initial elastic lateral stiffness but induces lower ductility and energy dissipation capacity in HSFTS-SLs. The performance of the specimens was comparable to that of the original sub-structure specimens after replacing shear links. Additionally, the expected post-earthquake recoverability and resilience of the structures could be achieved by replacing shear links. The acceptable residual interstory drift that allows for easy replacement of the bolted web-connected shear link was 0.23%. The bolted web-connected shear links had reliable hysteretic responses and deformation capacities. The connection rotation had a notable contribution to total link rotation. The results of the numerical analysis run for the proposed FEMs were consistent with the test results. It showed that the proposed FEMs could be used to investigate the seismic performance of the HSFTS-SL.

Seismic performance of eccentrically braced frames with high strength steel combination

Ming Lian,Mingzhou Su,Yan Guo 국제구조공학회 2015 Steel and Composite Structures, An International J Vol.18 No.6

Eccentrically braced frames (EBFs) often use conventional steel with medium yield strength. This system requires structural members with large cross-sections for well seismic behavior, which leads to increased material costs. In eccentrically braced frames with high strength steel combination (HSS-EBFs), links use Q345 steel (specified nominal yield strength 345 MPa), braces use Q345 steel or high strength steel while other structural members use high strength steel (e.g., steel Q460 with the nominal yield strength of 460 MPa or steel Q690 with the nominal yield strength of 690 MPa). For this approach can result in reduced steel consumption and increased economic efficiency. Several finite element models of both HSS-EBFs and EBFs are established in this paper. Nonlinear hysteretic analyses and nonlinear time history analyses are conducted to compare seismic performance and economy of HSS-EBFs versus EBFs. Results indicate that the seismic performance of HSS-EBFs is slightly poorer than that of EBFs under the same design conditions, and HSS-EBFs satisfy seismic design codes and reduce material costs.

THE LEARNING-TO-LEARN CURRICULUM REFORM IN HONG KONG AND SCHOOL EDUCATION FOR CHILDREN WITH SEVERE DISABILITIES

( Ming-gon John Lian ) 대구대학교 한국특수교육문제연구소 2014 Asia-Pacific Journal of Intellectual Disabilities Vol.1 No.1

Major educational reforms occur, in many countries, in an attempt to cope with the rapid- and constant-changing as well as technology-demanding modern life. The Education Commission in Hong Kong (HKEC) gave recommendations for educational reform to be geared toward life-long learning and whole-person development. To this, Hong Kong Curriculum Development Council (HKCDC) disseminated consultation document for reconstruction in school curriculum, including the advancement of nine generic skills in eight key learning areas. Special education practitioners are trying to follow the HKEC`s recommendations and the HKCDC`s guideline. A great number of task force activities and staff inservice workshops have been engaged. This paper shares the experiences and outcomes of recent curriculum development in schools for students with severe disabilities, including enhancement of generic skills through 8 major areas of learning

Seismic Story Shear Distribution Based on Inelastic State of Eccentrically Braced Frame with Vertical Link Composite High Strength Steel

Ming Lian,Shen Li,Xiaolei Li 한국강구조학회 2021 International Journal of Steel Structures Vol.21 No.4

The story shear distribution based on inelastic state of eccentrically braced frames with vertical link fabricated with high strength steel (Y-HSS-EBFs) are proposed in this paper, four groups of Y-HSS-EBF prototypes with diff erent stories are established in SAP2000 software. Moreover, the eff ects of structural height, velocity pulse of near-fault ground motions and acceleration cumulative eff ect of far-fault ground motions are considered. Nonlinear dynamic analyses are conducted to research the seismic story shear distribution of the structures under severe earthquakes. The story shear force distribution in inelastic state of Y-HSS-EBF is proposed based on equivalent base shear method provided in current design code, and the non-linear dynamic results are compared to lateral force distribution and other story shear distributions. The results indicated that near-fault earthquakes with velocity pulse and far-fault earthquakes with acceleration cumulative present diff erent eff ect on the seismic story shear distribution of structures, the story shear distribution of Y-HSS-EBFs proposed in this paper is very practical and it can be a reference for the performance-based seismic design method for Y-HSS-EBFs.

An iterative approach for time-domain flutter analysis of bridges based on restart technique

Wen-ming Zhang,Kai-rui Qian,Lian Xie,Lian Xie,Yao-jun Ge 한국풍공학회 2019 Wind and Structures, An International Journal (WAS Vol.28 No.3

This paper presents a restart iterative approach for time-domain flutter analysis of long-span bridges using the commercial FE package ANSYS. This approach utilizes the recursive formats of impulse-response-function expressions for bridge's aeroelastic forces. Nonlinear dynamic equilibrium equations are iteratively solved by using the restart technique in ANSYS, which enable the equilibrium state of system to get back to last moment absolutely during iterations. The condition for the onset of flutter instability becomes that, at a certain wind velocity, the amplitude of vibration is invariant with time. A long-span suspension bridge was taken as a numerical example to verify the applicability and accuracy of the proposed method by comparing calculated results with wind tunnel tests. The proposed method enables the bridge designers and engineering practitioners to carry out time-domain flutter analysis of bridges in commercial FE package ANSYS.

Curriculum and Assessment Adaptations for Students with Mild to Severe Mental and Multiple Disabilities in Hong Kong

John Lian, Ming-Gon 국립특수교육원 2004 The Asia-Pacific Journal of Inclusive Education Vol.1 No.-

School practitioners for students with mild to severe mental and multiple disabling conditions in Hong Kong are trying to cope with a series of evolutional changes in special education practices, including recent curriculum reform, inclusive education, and quality level school program advancement, so that their dedicated efforts can be more effective in enhancing their students' potential for inclusive schooling and/or living in an inclusive community. This paper will introduce these efforts for successful curriculum and assessment adaptations and related movements and activities that are initiated in Hong Kong, including alternative, authentic/functional, and portfolio assessment; and ecological approaches in school-based curriculum development and curriculum integration for learning to learn and life-long learning of students with mild to severe mental and multiple disabilities. Related implications such as effective instructional strategies, assistive technology, parental involvement and home-school partnership, program evaluation, and action research are also addressed.