Study On Correlation Between Garment Ease And Material Mechanical Properties And Its Prodicting Model

Although the relation between human body and garment is complex and vague,it is the basic study of garment fitting,three-dimensional virtual and fireproof garment security.This paper confirmed the basis of the theory of an objective evaluation for the virtual garment profile appearance from the engineering point of view based on the garment fitting,comfort and study of the combined relationship between material mechanical properties and garment ease capacity.The main works and approach in the study can be outlined as following.(1) Establishing mathematical algorithms of the ease between the body and the garmentDot cloud data of variety of sections or geometry algorithm of curve data was captured by using [TC]~2 scanner and body surface data points re-sampling methods.This paper obtained the coordinates of required characteristic section by use of re-sampling method(Conformal method), then established algorithm models of distance between body and garment both in normal and radial directions by using least squares and cubic polynomial approximation to fit curves of different sections,and confirmed the normal distance as the distance between human body and garment.Meanwhile,in accordance with the even arc-length the algorithm model of area ease was built.This paper used VB programming language to get distance ease and area ease with any angle, and defined these distance ease and area ease between body and garment as the garment profile ease.By calculating the normal and radial distance between body and garment at any random body sections angle,this paper found that the normal distance was more reasonable for body and garment ease than the radial distance.This was mainly because normal distance was the shortest from body to garment and it is the normal offset value in 3D virtual garment..According to the important part spec of garment plane cartography,characteristic sections of human body and garment were obtained,and sections above bust line were:shoulder width,bust width and back width section,sections under bust line were bust-full,waist-full and hip-full section.Analysis showed that distance between sections above bust line and garment was much shorter and less affected by garment ease,and research on these sections rarely helped to look for the main factors affecting the garment profile ease.On the contrary,sections under bust line were influenced by garment ease,and this paper studied these sections and analyzed main factors affecting the garment profile ease.This paper calculated and analyzed the distance ease of characteristic sections with different body angles,summed up the distance ease distribution relation between body and variety clothing sizes within the same garment style.The study showed that change of distance ease had certain change rules rather than evenly following the garment ease change,curve equation of change rules between distance ease and garment ease was been fitted according to certain angle.Distance ease in different sections had different change rules,for bust-full section,distance ease were smaller in back whenθwas from 120°to 135°,and the smallest in bust point whenθwas 240°.Distance ease in the back was bigger than in the front basically,and the most of the distance ease existed whenθwas between 150°to 210°.Because of arms,wave figure had amplitude whenθwas 165°or 195°,trough whenθwas 135°.As for waist-full section,distance ease distributed unevenly and got the biggest in the side whenθwas from 165°to 210°.In hip-full section, distance ease was much smaller in back whenθwas 90°and in the side whenθwas from 150°to 195°.In the front center whenθwas 270°,the distance ease was bigger than in back and besides. The most of the distance ease was in the princess line and formed a wave figure which had amplitude of the princess line position.By calculating and analyzing the area ease between body and garment with different clothing size,we found its change rule was similar with the distance ease,but was more useful for showing the details' change.For bust-full section,there was linear relation between area ease in the side and garment ease,and for waist-full section,there was quadratic equation between clothing sizes and area ease in the side,and summation area ease including the front and back.Besides,the proportion of area ease in the side took 70%of the total area ease could be used as area evaluation of garment-profile appearance.As for hip-full section,area ease was mainly in the front.(2) Ascertaining the main correlation factors which affect the garment-profile easeSeventeen mechanical properties of 31 different material had been tested,these material were classified as 6 species by using Cluster analysis,and one fabric of each species was selected as the sample coat fabric.Six patterns were selected as the sample jackets patterns from ten experimental patterns,so 36 jackets were made using the 6 selected material.By scanning these 36 sample jackets,we got the dot cloud data of model and sample jackets,obtained characteristic section, calculated garment-profile ease,analyzed the change of garment-profile ease distribution rule caused by different material mechanical properties and specs.The primary factors which affected different sections,distance ease and area ease in different angles were obtained by using step-by-step regression.Distance ease in bust section with different angle was almost not affected by material mechanical properties,whenθwas between 165°and 195°,distance ease was in a linear change along with the change of△B,the bigger△B was,the bigger distance ease was.Bust section area ease were comparatively invariable in the front and back of human body due to the chest and scapular bone,and it also did not affected by△B and material mechanical properties.△B,lgw and lg2HB were main factors which affected the area ease in the side of body..Distance ease in waist section within different angle was significantly affected by△B and△W,little affected by material mechanical properties.△W was the main factor which affected the area ease in the back and side of human body while△W and lg2HB5 were the main factors witch affected the area ease in the front of human body.Distance ease in hip section was significantly affected by 2HG and F whenθwas between 90°and 120°,and affected by lg2HB whenθwas between 225°and 270°.2HG was the main factor to affect the area ease in the back of human body;△H and lgw were the main factors to affect the area ease in the side of human body and△H,2HG and F were to the front.The angles in front bust and waist partition lines changed slightly while angles in hip had an orderly change.The partition lines in front of hip had significant correlation with G,2HG and lgw, and no correlation with other factors especially with△B,△W and△H.The primary factor to affect partition lines in front of hip was established as lgw(fabric weight) by using step-by-step regression.(3) Establishing the objective evaluation method for the virtual garment-profile appearance and prediction systemThrough Friedman,we found that the subjective evaluation of 7 experts to the jackets profile appearance were accordant.We made an objective evaluation to jackets according to set proportion of side waist area and total waist area,and we found the consistency between subjective evaluation and objective evaluation though Spearman rank correlation coefficient test method.Thus,we confirmed that it was feasible to take the proportion of side waist area and total waist area as an objective evaluation of testing wearing garment profile appearance. By analyzing objective effect of jackets in the same specs and made of the same material,we found garment ease is the main factor affecting the wearing garment profile appearance.When the ease get a certain degree,material mechanical properties had little effect to the wearing garment profile appearance,and it would not affect the wearing garment profile appearance.However, material mechanical properties affected garment appearance increasingly when the garment ease was getting smaller.Fabric having smaller 2HG obtained a better appearance.Meanwhile,smaller ease brought smaller space between garment and body,so we adjusted sample jackets according to body figure and reformed patterns to make jackets with different mechanical properties have a good wearing appearance.This paper established multiple regression model and BP neural network model about the objective evaluation of garment profile appearance.From the predictive test,we found that neural network predicted values were much closer to the measured values than the multiple regression predicted values.This showed that that neural network prediction model is more precise than the multiple regression prediction models.According to the OpenGL software surface display theory,dot data was been showed as the shape of the surface,so pictures of manikin and the virtual three-dimensional jackets profile appearance had been saw,but with different fabric mechanical properties,the jackets profile appearance appeared differently.We had constructed a visualization predict system of virtual garment wearing profile appearance,and this system can judge garment wearing profile appearance based on the known fabric mechanical properties and garment specs.That system could also collect information about the certain garment wearing profile appearance:①the garment wearing profile appearance value.②judgment of garment wearing profile appearance,sample garment try-on and judgment of pattern reform necessity.③pictures which was mostly close to the three-dimensional virtual garment profile appearance.The reliability of this predicting system was been proved through testing jacket.