Modeling and Simulation of Human Body Heat Transfer System Based on Air Space Values in 3D Clothing Model

Comfort can be considered as subjective feeling, which could be affected by the external ambient, by the physical activity, and by clothing. Considering the human body heat transfer system, it mainly depends on various parameters including clothing materials, external and internal environment, etc. The purpose of the current paper is to study and establish a quantitative relationship between one of the clothing parameters, ease allowance (air gap values) and the heat transfer through the human body to clothing materials and then to the environment. The study considered clothing which is integrated with the 3D ease allowance from the anthropometric and morphological data. Such incorporating of the clothing’s 3D ease control was essential to properly manage the air space between the body and the proposed clothing thermal regulation model. In the context of thermal comfort, a clothing system consisting of the human body, an ease allowance under clothing, a layer of textile materials, and a peripheral layer adjacent to the textile material was used. For the complete system, the heat transfer from the skin to the environment, which is influenced by thermoregulation of the human body, air gap, tissue, and environmental conditions were also considered. To model and predict the heat transfer between the human body and the temperature of skin and clothes, a 3D adaptive garment which could be adjusted with ease allowance was used. In the paper, a thermoregulatory model was developed and proposed to predict the temperature and heat within clothing material, skin, and air space. Based on the result, in general the main difference in the temperature of clothing and skin from segment to segment is due to the uneven distribution of air layers under the clothing.

Calculating the Percentage of Body Measurement Changes In Dynamic Postures In Order To Provide Fit In Skiwear

The aim of this study is to investigate the local body measurement changes in movements during Alpine skiing and to calculate these changes in "percentages" in order to use in garment pattern preparing process to achieve the best clothing comfort characteristics in alpine skiing suits. For that purpose, an anthropometric measurement study was conducted, which involved measuring 31 male volunteer’s body sizes in static and dynamic postures. Within this context, the sizes to be measured were identified as static and dynamic by specifying the anthropometric landmarks on the body using ISAK (The International Society for the Advancement of Kinanthropometry) practices as the base. It was found that percentage changes in the anterior knee length, anterior leg length, hip length, elbow length and posterior arm length were 43%, 2%, 35%, 40% and 9%, respectively, from the measurements collected from 31 male recreational Alpine skiers. Afterwards, regarding to the obtained data, the three body dimensions such as inseam, back waist rise and sleeve length were re-calculated to use in the preparing of pattern for tight-fitting garments. Ultimately, a base layer thermal bottom’s garment patterns were developed and evaluated using a 3D virtual try-on system. Consequently, it was found that the inseam length and sleeve length should be reduced while the back waist rise needs extra ease allowance. With respect to the virtual fitting, the developed pattern was more fit than the original pattern and had more ability to adapt dynamic postures.

Suitable ranges of ease allowance for appearance of women's shirts of fit and straight styles

PurposeThis study investigated changes in appearance due to variations in the amount of ease allowance at the bust, waist and hips with ready-made women's shirts in two different styles. The authors also examined the suitable range for ease allowance with those two styles using a sensory test for evaluating appearance.Design/methodology/approachThe authors employed two women's shirts (samples I and II) in different styles (fit and straight). The authors modified the size of the bust, waist and hips with a changeable-size dress form using 1-cm intervals. The authors observed the shape changes. With the pictures at 2-cm intervals, the authors conducted a sensory test to evaluate appearance. 20 Japanese university students in their 20s made their assessments using seven items (wrinkles, fit, silhouette, beauty, fashionable impression, comfort and purchase intention) with a five-point scale. The proportion of subjects who scored 1 or more was 40% or greater when using ease allowance in the suitable range.FindingsThe appropriate ranges of ease allowance differed according to the style and evaluation items. Regarding appearance and purchase intention with sample I from the front, the suitable range of ease allowance was 1–7 cm for the bust, 2–6 cm for the hips and 13 cm for the waist. From the side, the range was 0–6 cm for the hips and 7 cm for the bust. With sample II from the front, the suitable range of ease allowance was about 4 cm for all parts. From the side, the range was 11 cm for the bust and 4 cm for the hips.Originality/valueUsing a dress form, the authors determined suitable ranges of ease allowance for two women's shirts in fit and straight styles with seven bust, six waist and six hip sizes. The authors found that the suitable range of ease allowance varied according to the style, direction and parts of the shirt. Our results can act as a guideline for designing and selecting ease allowance for women's shirts, taking into account comfort from appearance, purchase intention and beauty.

The impact of body surface convex angle on dressed waist ease

PurposeThe comfort and fit of clothes are affected by fabric properties, dressed ease and environmental conditions, in which dressed ease is influenced by the interaction among complex shapes of human body, style design and fabric mechanical properties.Design/methodology/approachIn this study, the dressed ease distribution at waist section, which is related to body surface convex angle, was investigated using 3D scanning. A series of surface convex angles on bust and back were formed after adjusting the mannequin. The mannequin was scanned by TC2 separately in garments with eight different ease allowances. Then the dressed ease distributions at waist under different convex angles of body surface have been acquired by calculating the distance between waist points and dressed surfaces along normal directions.FindingsThe results showed that the body surface convex angle was weakly related to the dressed ease when the garments’ bust ease allowance was below 4 cm. When the garments’ bust ease allowance was within 6–12 cm, the body convex angle had a great impact on the dressed waist ease distribution in the condition of 26º–33º bust convex angle and 13.96º–17.96º back slope angle. For slack garments with more than 16 cm ease allowance, the dressed waist ease distribution did not relate to the bust convex angle, while it strongly related to the bust convex angle between 13.96º and 17.96º. The regression model was statistically significant between the dressed ease value and the body surface convex angle.Originality/valueAccording to the dressed waist ease distribution of different body surface convex angles, this paper gives an application of pattern modification in order to optimize the waist fit. The results can provide guidance for the optimization of different body shapes. At the same time, the application of gap data to 3D virtual fitting can greatly improve the authenticity of virtual simulation effect.

Fast custom apparel design and simulation for future demand-driven manufacturing

Purpose A common pipeline of apparel design and simulation is adjusting 2D apparel patterns, putting them onto a virtual human model and performing 3D physically based simulation. However, manually adjusting 2D apparel patterns and performing simulations require repetitive adjustments and trials in order to achieve satisfactory results. To support future made-to-fit apparel design and manufacturing, efficient tools for fast custom design purposes are desired. The purpose of this paper is to propose a method to automatically adjust 2D apparel patterns and rapidly generate acustom apparel style for a given human model. Design/methodology/approach The authors first pre-define a set of constraints using feature points, feature lines and ease allowance for existing apparels and human models. The authors formulate the apparel fitting to a human model, as a process of optimization using these predefined constraints. Then, the authors iteratively solve the problem by minimizing the total fitting metric. Findings The authors observed that through reusing existing apparel styles, the process of designing apparels can be greatly simplified. The authors used a new fitting function to measure the geometric fitting of corresponding feature points/lines between apparels and a human model. Then, the optimized 2D patterns are automatically obtained by minimizing the matching function. The authors’ experiments show that the authors’ approach can increase the reusability of existing apparel styles and improve apparel design efficiency. Research limitations/implications There are some limitations. First, in order to achieve interactive performance, the authors’ current 3D simulation does not detect collision within or between adjacent apparel surfaces. Second, the authors’ did not consider multiple layer apparels. It is non-trivial to define ease allowance between multiple layers. Originality/value The authors use a set of constraints such as ease allowance, feature points, feature lines, etc. for existing apparels and human models. The authors define a few new fitting functions using these pre-specified constraints. During physics-driven simulation, the authors iteratively minimize these fitting functions.

Virtual try-on technologies in the clothing industry: basic block pattern modification

Purpose The purpose of this paper is to investigate basic block pattern modification according to fabric used and the mismatch between 2D and 3D measure lines at bust, waist and hip girths when ease allowance is changed uniformly. Design/methodology/approach For the investigation, virtual try-on software Modaris 3D Fit (CAD Lectra) was used. The straight shape dress fitting was done using seven cotton and cotton blended plain weave fabrics. After virtual try-on, the mismatch d (dbust, dwaist, dhip) between 2D and 3D measure lines was measured in order to determine base pattern adjustments using different fabrics. Findings It was found that the position and length of 3D measure lines at bust, waist and hip girths does not match the position and length of corresponding lines in 2D base patterns after virtual try-on due to fabrics deformation, which is related to mechanical properties. It was proved that derived linear equations presenting a relation between mismatch and ease allowance values could be used for basic block pattern modification that 3D and 2D measure lines would coincide during clothing try-on. Research limitations/implications This research is limited to cotton/cotton blended woven fabrics and straight dress; therefore, other fabric types and other clothing could be investigated in the future to expand data basis. Practical implications The main practical point of the proposed method is that in order to obtain particular 3D ease value in a garment, it can be calculated from 2D ease allowance value and the fabric’s tensile properties using linear equations. The basic block patterns could be modified using this method not only for tested fabrics but also for other fabrics with similar composition, structural and mechanical properties. 3D ease values in garment can be easily checked by using virtual try-on technology without production of real prototypes. The method is applicable for making ready-to-wear or individually tailored clothing. Originality/value The proposed method in this paper presented opportunity to modify the basic block patterns of the dress according to the fabric’s tensile properties and 2D ease allowance. The basic block patterns could be modified according to presented linear functions for each tested fabric. The application of this method can fully ensure the interaction between the garment 2D patterns to 3D garment so that a desired 3D garment fitting effect to the body can easily be satisfied by the adjustment of particular fabric characteristics. It offers further possibilities, especially with developing virtual try-on technologies.

Apparel ease distribution analysis using three-dimensional motion capture

When an ease allowance at a body landmark is given, the ease distribution along the circumference at this landmark can still change with the wearing circumstance. This paper investigates both static and dynamic ease distributions of clothes at bust and waist lines by using a three-dimensional motion capture system (3DMCS). Female participants with the same body type were recruited to conduct experiments to examine how ease distributions change with body motions. Specific markers provided with the 3DMCS were adhered to the surfaces of a participant and her clothes along the bust and waist lines, and the coordinates of the markers were tracked by the 3DMCS while the participant walked on a treadmill at different speeds. It was found that the static ease distributions showed different patterns at different body landmark lines. At the bust, the ease tended to concentrate more in the left and right regions, while the ease at the waist appeared to be gathered more in the front and back regions. In the dynamic tests, ease variations at different clothes markers on the waistline exhibited very different changing patterns. The ease variations of the markers in the same region (e.g., left and front) were positively correlated ( r = 0.863), while those in regions symmetrical to the y-axis (left–right) were negatively correlated ( r = –0.738) and those in regions symmetrical to the x-axis (front–back) were weakly correlated ( r = 0.541). Both the frequency and the magnitude of ease variations seemed to be incremental to the walking speed, although the concentration areas of ease remained unchanged.