• Title/Summary/Keyword: deflection and stress analysis

Search Result 356, Processing Time 0.025 seconds

On the post-buckling behaviour of plates under stress gradient

  • Bedair, Osama K.
    • Structural Engineering and Mechanics
    • /
    • v.4 no.4
    • /
    • pp.397-413
    • /
    • 1996
  • In this paper the elastic post-buckling behaviour of plates under non-uniform compressive edge stress is investigated. The compatibility differential equations is first solved analytically and then an approximate solution of the equilibrium equation is obtained using the Galerkin method. Explicit expressions are derived for the load-deflection, ultimate strength and membrane stress distributions. Analytical effective width formulations, based on the characteristics of the stress field of the buckled plate, are proposed for this general loading condition. The predicted load-deflection expression is compared with independent test results. Results are also presented detailing the load-deflection behaviour and stress distribution for various aspect ratios.

Stress and Deflection Analysis of Steel Beams at Elevated Temperature (온도상승에 따른 Steel-beam의 응력 및 처짐 해석)

  • Jang, Myung-Woong;Kang, Moon-Myung;Kang, Sung-Duk
    • Journal of Korean Association for Spatial Structures
    • /
    • v.3 no.1 s.7
    • /
    • pp.57-68
    • /
    • 2003
  • This paper have performed to investigate the influence of certain parameters, including the boundary condition types, load ratios of the steel beams, and span/depth ratios of the beams itself on the structural behaviour of the steel beams at elevated temperatures. This paper is analysed the stress and vertical deflection at mid-span of the steel beams at elevated temperatures and also predicted 'failure' temperatures of the steel beams at elevated temperatures. Fire analysis used here is analysed by software VULCAN. Design examples are given to describe the structural behaviour of the steel beams at elevated temperatures.

  • PDF

Experimental and numerical study on pre-cambered deep deck-plate system

  • Seung-Ho, Choi;Inwook, Heo;Khaliunaa, Darkhanbat;Sung-Mo, Choi;Kang Su, Kim
    • Computers and Concrete
    • /
    • v.30 no.6
    • /
    • pp.445-453
    • /
    • 2022
  • A pre-cambered deep deck-plate system has been developed that can realize a long span by offsetting the deflection caused by a construction load. In this study, finite element (FE) analysis is performed to examine the preload-camber relationship introduced into a deck and calculate the deflection reflecting the ponding effect that arises during concrete pouring. The FE analysis results showed that the stress of the bottom plate was half of the yield stress when the pre-camber of approximately 30 mm was introduced. Based on the FE results, a full-scale deep deck-plate is fabricated, a pre-camber is introduced, and concrete is poured to measure deflection. A deflection calculation formula that reflects the ponding effect is proposed, and the deflections yielded by the proposed model, experimental results, and FE results are compared. Results show that the proposed model can accurately estimate the deflection of non-supported deep deck-plate systems after concrete is poured.

Automatic Analysis of Continuous Beams with Variable Cross-Section (다경간 연속보의 자동화 해석)

  • Shin, Seong-Cheol;Kim, Young-Il;Lee, Tae-Eun;Lee, Byoung-Koo
    • Proceedings of the Korean Society of Agricultural Engineers Conference
    • /
    • 2001.10a
    • /
    • pp.198-201
    • /
    • 2001
  • This paper deals with the Automatic Analysis of Continuous Beams with Variable Cross-Section. Based on the principle of superpositon and the method of consistent deformations, the governing differential equation is derived for the deflection and stress resultants of such continuous beam. The effects of variable load conditions, the end constraints on the deflection and the stress resultants are analyzed. It is expected that the results obtained herein can be used practically in the structural engineering.

  • PDF

Structural Performance Evaluation on Stress-Laminated Timber Bridge Deck Using Finite Element Analysis (유한요소해석을 이용한 응력적층 바닥판의 구조성능평가)

  • Shin, Yukyung;Eom, Chang-Deuk;Lee, Sang-Joon
    • Journal of the Korean Wood Science and Technology
    • /
    • v.42 no.1
    • /
    • pp.20-26
    • /
    • 2014
  • This paper represented the finite element analysis to estimate structural performance of stress-laminated deck, which is determined by deflection, stress, and aging characteristics of tensioning. After loading, the deflected shape showed plate behavior because pre-stressing make frictional force between each member. Compared between initial post-tension and the results, pre-stressing forces were decreased with deck deflection. This is because deflection occurred in the deck so that pre-stressing decreased due to load reduction. However, material plasticity was not considered so that advanced researches should be performed.

Joint stress based deflection limits for transmission line towers

  • Gayathri, B.;Ramalingam, Raghavan
    • Steel and Composite Structures
    • /
    • v.26 no.1
    • /
    • pp.45-53
    • /
    • 2018
  • Experimental investigations have revealed significant mismatches between analytical estimates and experimentally measured deflections of transmission towers. These are attributed to bolt slip and joint flexibility. This study focuses on effects of joint flexibility on tower deflections and proposes criterions for permissible deflection limits based on the stresses in joints. The objective has been framed given that guidelines are not available in the codes of practices for transmission towers with regard to the permissible limits of deflection. The analysis procedure is geometric and material nonlinear with consideration of joint flexibility in the form of extension or contraction of the cover plates. The deflections due to bolt slip are included in the study by scaling up the deflections obtained from analysis by a factor. Using the results of the analysis, deflection limits for the towers are proposed by limiting the stresses in the joints. The obtained limits are then applied to a new full scale tower to demonstrate the application of the current study.

Dynamic Analysis of Boom Using Finite Element Method (유한 요소법을 이용한 붐대의 동특성 해석)

  • Han, Su-Hyun;Kim, Byung-Jin;Hong, Dong-Pyo;Tae, Sin-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2005.05a
    • /
    • pp.987-991
    • /
    • 2005
  • The Aerial platform Truck is widely used for work in high place with the aerial platform. The most important thing is that worker's safety and worker must be able to work with trustworthiness so it needs to be verified its stiffness, deflection of boom, and dynamic condition concerned with a rollover accident. It should have an analytical exactitude because it is directly linked with the worker safety. In this point, we are trying to develop a proper CAE analysis model concerned with a rollover safety, bending stress and deflection for load. The Aerial platform Truck have a dynamic characteristics by load and moving of boom in the work field, so its static and dynamic strength analysis, structural mechanics are very important. Therefore, we evaluate the safety of each boom to calculating its stress, deflection. A computer simulation program is used widely for doing applying calculation of stiffness and structural mechanics, then finally trying to find a optimum design of the Aerial platform Truck.

  • PDF

Numerical analysis of simply supported one-way reinforced concrete slabs under fire condition

  • Ding, Fa-xing;Wang, Wenjun;Jiang, Binhui;Wang, Liping;Liu, Xuemei
    • Computers and Concrete
    • /
    • v.27 no.4
    • /
    • pp.355-367
    • /
    • 2021
  • This paper investigates the mechanical response of simply supported one-way reinforced concrete slabs under fire through numerical analysis. The numerical model is constructed using the software ABAQUS, and verified by experimental results. Generally, mechanical response of the slab can be divided into four stages, accompanied with drastic stress redistribution. In the first stage, the bottom of the slab is under tension and the top is under compression. In the second stage, stress at bottom of the slab becomes compression due to thermal expansion, with the tension zone at the mid-span section moving up along the thickness of the slab. In the third stage, compression stress at bottom of the slab starts to decrease with the deflection of the slab increasing significantly. In the fourth stage, the bottom of the slab is under tension again, eventually leading to cracking of the slab. Parametric studies were further performed to investigate the effects of load ratio, thickness of protective layer, width-span ratio and slab thickness on the performance of the slab. Results show that increasing the thickness of the slab or reducing the load ratio can significantly postpone the time that deflection of the slab reaches span/20 under fire. It is also worth noting that slabs with the span ratio of 1:1 reached a deflection of span/20 22 min less than those of 1:3. The thickness of protective layer has little effect on performance of the slab until it reaches a deflection of span/20, but its effect becomes obvious in the late stages of fire.

Analysis of Load Transmission Characteristics for Automobile Helical Gear (자동차 헬리컬기어의 하중전달 특성해석)

  • Park, C.I.;Lee, J.M.
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.3 no.5
    • /
    • pp.1-9
    • /
    • 1995
  • The purpose of this study is to develop a computer simulation program for analyzing load transmission characteristics of a helical gear system in design stage. In this analysis, the rotational delay, load distribution, root stress, and contact area are investigated. That is, the influence function of deflection is obtained by finite element analysis and the influence function of approach and gear tooth error are considered. Load distribution, rotational delay, and contact area are calculated by solving load-deflection equation which includes these influence functions and tooth error, and the influence function of the bending moment is obtained by finite element analysis. The root stress is calculated by the load distribution and the influence function of the bending moment. The results of the simulation are cross-checked through a specially designed experimental set-up.

  • PDF

AN ANALYSIS OF STRESS DISTRIBUTION IN THE CASE OF UNILATERAL MOLAR EXPANSION WITH PRECISION LINGUAL ARCH BY FINITE ELEMENT METHOD (구치 편측확장을 위한 Precision Lingual Arch 적용시 응력분포에 관한 유한요소법적 연구)

  • Koo, Bon-Chan;Sohn, Byung-Wha
    • The korean journal of orthodontics
    • /
    • v.24 no.3 s.46
    • /
    • pp.721-733
    • /
    • 1994
  • Orthodontic tooth movement is closely related to the stress on the periodontal tissue. In this research the finite element method was used to observe the stress distribution and to find the best condition for effective tooth movement in the case of unilateral molar expansion. The author constructed the model of lower dental arch of average Korean adult and used $.032'\times.032'\times60mm$ TMA wire. The wire was deflected in the horizontal and vertical direction to give the 16 conditions. The following results were obtained ; 1. When the moment and force were controlled properly the movement of anchor tooth was minimized and the movement of moving tooth was maximized. 2. As the initial horizontal deflection increased the buccal displacement of both teeth was also increased. As the initial horizontal deflection increased the lingual movement of anchor tooth and the buccal movement of moving tooth increased. 3. When the initial horizontal and vertical deflection rate was 1.5 the effective movement of moving tooth was observed with minimal displacement of anchor tooth.

  • PDF