Study On Creep Deformation And Various Failures Modes On The Fabric Clip

The stenter is most widely used in dyeing,bleaching and printing process with the function of stretching the fabric along the width direction.The fabric’s fixture(clip)is one of the most important assembly component used in the mercerizing machine and stretching machine to ensure that the fabric has a good shaping effect avoiding the emergence of “lotus leaf”,“broken edge” and other defects.However,during the fabric finishing process,the fabric clip is subjected to fail inside the stenter chambers due to several parameters such as the thermal and mechanical load at high temperature which results in clip off failure phenomenon.Therefore,whether the fabric production enterprises,or the use of manufacturers,are considering about the failure of the component and researching on the measures of prolonging the service life.This paper combined with the test data,under high temperature(230)and continuous working condition(260days),researched on the failure modes of the clip from the aspects of materials,processing and installation,operating conditions through finite element analysis of the clip provided by a machinery manufacturing company.The objectives mentioned above were achieved as detailed below:1.A fabric elongation test was performed by using 2 different types of fabric specimen for various pulling forces along the warp and weft side.Assumed a small degree of wear on the sliding contact between the shaft and the clip body,half symmetry model of the clip was created to analyze the contact stress distribution on the blade and the relationship between clamping angle and clamping fastness for the various pulling forces(100N,200 N,300N)under different blade shape by using ABAQUS.2.According to the heat transfer theory,heat conduction in high temperature fabric,thermal boundary conditions and loading form were studied.Simulated the fabric temperature field,thermal deformation and thermal stress distribution through the transient thermal structural coupled method.Analyzed the different assembly modes between clip body axis and hole(clearance and interference)in order to find he impact of the clip plate deformation,also the clamping fastness was further studied.3.At high temperature 230 for the various pulling forces(100N,200 N,300N)the creep deformation on the clip body hole(A380 aluminum alloy)was analyzed.The simulation results showed that the creep strain increases as much as the time increases.A dimensional change and distortion test were performed on three different clip bodies at various time periods(50 days,200 days,260 days)by using a CMM test machine.The dimensional change test data on the clip body hole were compared to the numerical analysis of the creep deformation on the clip body.The test results and the numerical results showed a good agreement.4.The main factors causing fabric clip failure such as creep,mechanical load and thermal deformation were analyzed.Also,we explored different methods to improve the service life of the fabric clip.At high temperature for a constant pulling force of 300 N,the fabric clip failure lifetime was calculated by using the analytical method and finite element method.