A Study of Elevator Counterweight Derailment Mechanism and Strengthening Methods

• Main Authors: Yun-Shuan Horng, 洪筠萱
• Other Authors: G. C. Yao
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/75855223240164133470

碩士 === 國立成功大學 === 建築學系碩博士班 === 91 === The vulnerability of elevator systems in the earthquake has two factors. They are derailed counterweight, fallen counter-weights, and a derailed car. The damage of side rails is the most significant cause of destruction in elevator systems. As a result, this paper discusses the derailment mechanism, and uses full-scale and one span experiments to study 5K rails' derailment deform behaviors and strengthening methods. The experiment contents include in plane and out-of-plane ones. The experiment uses the dynamic H-actor provide force on the rail model, including dead load and sinusoidal excitation. So as to find in plane and out-of-plane load tests on 5K guide rails were performed. To verify the effectiveness of different strengthening methods, four types were tested: Epoxy reinforced 5K rails, the replacement of 8K rails, and shortened 5K and 8K rails' bracket distance. The study conclusions find that the internal common formula of seismic designs underestimates 5K rails in plane's maximum load, and overestimates their displacement when suffer exterior force. Tests on the derailment mechanism lead to the conclusion that the rail been impacted upon in both directions will deform into plastic behavior but short of derailment. It is the other rail, only loaded in the Y-direction, will experience large separation from the guide shoes in the X-direction and leads to the derailment of the counterweight. From rails' cycle loading experiments, we found their afford high-displacement is about equal to 5K rails' elastic displacement, 5K rails' large residual displacement influences rails' safety as decreasing loading force. The internal common formula of seismic designs is unapplied. From the result of experiments, 5K rails' seismic acceleration rate is 0.23g, lower than the internal common formula of seismic designs in Taiwan's first earthquake zone and equal to Taiwan's second earthquake zone. 8K rails' seismic acceleration rate is 0.27g, lower than the internal common formula of seismic designs in Taiwan's first earthquake zone, and higher than Taiwan's second earthquake zone. Epoxy reinforced 5K rails：they can't strengthen rails' stiffness very well in elastic stage, but very well in inelastic stage. Epoxy reinforced 5K rails can bear more force. 8K rails：they strengthen obvious stiffness, and the balance of moving is good. Shortened 5K rails：their bracket span's distance strengthens stiffness very obviously. But shortened 5K rails' bracket span distance's stiffness is too high to rift the roller guide. Shortened 8K rails：they strengthens rails' stiffness more obviously, but its stiffness is either too high to break the roller guide.