An elevator is a typical flexible lifting machine. In order to monitor the vibration of structure, characteristics an with traction ratio 1:1 has been tested experimentally. Sensors were arranged on platform frame, car roof, and hoist rope test vibrations in both ascending descending conditions. The transverse, longitudinal, coupled transverse-longitudinal compared analyzed. Further, short-time Fourier transform (STFT) method was used examine power spectral density (PSD) results, main...

In order to study the dynamic characteristics of elevator, response elevator under normal operation and emergency braking conditions are analyzed. this paper, centralized mass discretization model is used vibration traction system external excitation. Firstly, equation multi-degrees-of-freedom (abbreviated as DOF) established. Then, three DOF analyzed, natural frequencies modes obtained. The free forced obtained, theoretical solutions Finally, test method proposed in paper elevator. results...

In order to improve the inspection efficiency and accuracy of braking capacity elevator brake being used, a novel method for analyzing full‐loaded performance by using unloaded is proposed, set methods measuring torque designed. Based on analysis key factors that affect mechanical brake, calculation model in process emergency with traction ratio 2 : 1 established, relationship between acceleration under different working conditions analyzed. It shown that, assumed, 1.56 times static 1.25...

Buried pipelines are prone to deformation under surface displacement, pressure occupation, and/or other actions, resulting in stress concentration. Conducting regular detection is an important approach reducing pipeline accidents. This study performed experiments on measuring the coercivity of X80 steel, most commonly used material for high-pressure large-diameter gas transmission pipelines. The specimen different combinations was measured using DC-driven coercive force measurement system,...

An elevator traction system is simplified as a damped vibration system. In order to study the damping characteristics of an system, this paper tests car frame on in-service with ratio 2:1. The results show that natural frequency and stiffness decrease increase load; attenuation coefficient Furthermore, related initial running direction. Under same load, value downward greater than upward. This research establishes relationship between parameters, load direction provides approach solve...

The governing equation of the bending problem simply supported thin plate on Pasternak foundation is degraded into two coupled lower order differential equations using intermediate variable, which are a Helmholtz and Laplace equation. A new solution two-dimensional operator proposed as shown in Appendix 1. R-function basic solutions used to construct corresponding quasi-Green function. quasi-Green’s functions satisfy homogeneous boundary conditions problem. transformed integral applying...

In order to study the relationship between braking distance and load of escalator realize prediction rated with a little load, method combining theoretical analysis experimental research is used. First, dynamic characteristics during emergency are analyzed, model under different loads derived based on law conservation energy. Furthermore, influence coefficients were determined through studies, was revised, concept equivalent no-load kinetic energy (ENKE) proposed. The shows that increases...

<h2>Abstract</h2> The free vibration control differential equation of shallow spherical shell on two-parameter foundation is a four order equation. Using the intermediate variable, reduced to two lower equations. first Helmholtz A new method two-dimensional operator proposed as shown in paper which Bessel function included needs be treated appropriately eliminate singularity. transformed into integral using paper. second Laplace by existing methods. Then equations are discretized according...

In order to analyze emergency stop vibration of the friction vertical lifting system under different loads, a loading experiment was carried out, and longitudinal characteristics carriage, frame, steel rope were measured during braking process an elevator. Accordingly, it is found that load mass does not affect peak deceleration value car frame wire downwards stop. Then, explored using time-varying analysis theory. The obtained results show when analyzing objects on both sides traction...

The governing differential equations of the bending problem simply supported shallow spherical shells on Winkler foundation are simplified to an independent equation radial deflection. deflection is decomposed two Laplace operators by intermediate variable. R-function theory applied describe a shell with concave boundary, and then quasi-Green’s function established using fundamental solution normalized boundary equation. satisfies homogeneous condition problem. reduced simultaneous Fredholm...

In order to improve the safety of hook, hook was finite element analyzed.Firstly, geometric model and were created.Then material parameters boundary conditions applied model, load studied specially.Finally, static strength fatigue life analysis carried on.The results indicate that maximum stress 93.5MPa, less than allowable value, minimum 34 thousand times, commuted theoretical 6.9 years.This method can reflect life, provide a reference for improving hook.