The Improvement Of Measuring Method For Unidirectional Fabric And Evaluation Of Drape

Drape of fabric refers to the performance of fabric drooping due to gravity.It is one of the importance contents of fabric visual style and aesthetic comfort.The principle of most traditional drape measurement is based on the umbrella projection method,which mesures the deformation of a horizontal specimen subjected to gravity perpendicular to its plane.therefore,the principle of the umbrella projection method is not in accordance with the force in actual use of fabric,And the umbrella projection method has great error in measuring some perforated fabrics.For the limitations of umbrella projection method in this paper,proposed an improvement method based on the proposed unidirectional drapability measurement method,and proposed a new evaluation of unidirectional drapability combined with fuzzy clustering.The measuring method of unidirectional drapability refers to simulating curtain and other fabric to keeping the end fixed,and the other end naturally droop,and put a 3D scanner on the front of sample,the 3D scanner continuously scan the sample to building 3D model,and obtain two dimensional suspended projection curves from 3d models when it is naturally droopped,and extract unidirectional drape parameters from two dimensional suspended projection curves and use these parameters to establishing evaluation system.Through proposing the improvement and optimization of measuring method of unidirectional drapability,including the design of the way of three dimension scanning?the design of the track of scanning movement?the optimization of two dimensional suspended projection curves,proposed a new method of extracting characteristic parameters of unidirectional drapability,and use these characteristic parameters to proposing a new method of evaluating unidirectional drapability.The principle of designing the way of 3D scanning is according to adjusting the scanner's scanning angle and start position to obtain more accurate outline information of the bottom of sample,effectively solved the problem of absence of crest information due to the curl of the outline,the design theory of the track of scanning movement is according to obtaining 3D model rely on stable and repetitive scanning to satisfy precision requirement,stable scanning can reduce the interference of noise point,repetitive scanning can greatly improve the scanning accuracy.The optimization of two dimensional suspended projection curves reflected in using filter algorithm to removing noise point,laid the foundation of extracting characteristic parameters from projection curve,the extract of characteristic parameters of unidirectional drapability refers to using characteristic parameters such as peak height ? peak width ? wave curvature and bend index to represent the unidirectional drapability.and use fuzzy clustering to verify the reasonability of the characteristic parameters in the last.In order to verify the reasonability of the characteristic parameters and the feasibility of using fuzzy clustering to establish evaluation system of unidirectional drapability,selected more than thirty samples including all kinds of fabrics,these samples were divided into four grades:”good”,“better”,”medium”,”bad”through subjective assessment in the two aspects of degree of suspension and form of suspension.measured all characteristic parameters of samples in the measuring equipment of unidirectional drapability,and the fuzzy clustering analysis was carried out by using the similarity degree of each drape parameters,through comparing the result of fuzzy clustering with subjective evaluation,the result show that fuzzy clustering result and subjective evaluation result are consistent,it is proved that the extraction of characteristic parameters can properly express the unidirectional fabric drapability,the evaluation method of unidirectional drapability based on fuzzy clustering is feasible.