为探究不同胸型胸围截面的压力—位移变化,文章采用三维扫描仪获取136名女体躯干数据,提取重建坐标系下的乳房深与乳房宽比值,从而将胸型分为6类.建立相对应的有限元接触模型,模拟不同受压状态下6类胸型对应截面的受压与位移变化,构建了"(压力/位移)—角度"曲线及其函数关系.研究表明,外力作用下胸围截面BP点应力最大,其次是后侧位置,曲率较大且位置突出处应力较大.随着乳房形态逐渐变大,胸部及人体侧面软组织层变厚,体表形变增大且呈现外扩趋势,结果可为紧身服装压力舒适性研究提供参考.
With the rapid advancement of apparel technology and the increasing demand for healthy life,people have higher requirements for the comfort of apparel.For it,pressure comfort is an important influence factor of clothing comfort.And the size of body surface displacement after the human body is pressurized is closely related to the pressure comfort.Therefore,it is of great significance to investigate the change rule of pressure and body surface displacement for the study of pressure comfort.However,due to the influence of the difference of bust type,the pressure state and morphology changes of each part of female body bust cross-section are different.Besides,different body types will show different patterns of change when they are subjected to external forces.Therefore,when exploring the change rule of body surface morphology,it is necessary to take the difference of bust type into account. We explored the pressure and displacement changes of the bust section of different bust types through the finite element simulation method.The study mainly includes three parts: i)Data acquisition and bust type classification:a 3D scanner was used to obtain 136 3D point cloud data of female bodies with different bust types,and the reverse engineering software Geomagic was used to pre-process the 3D data and extract the breast parameters under the reconstructed coordinate system.In addition,there are six categories of bust shapes based on the ratio of breast depth to breast width. ii)Finite element modeling and simulation:the processed surface data of the bust section and the inner structural data were assembled to generate the geometric model of female bust section by different types.On this basis,the corresponding finite element contact model was established,and five kinds of uniform normal pressures were applied to it.It is used to simulate the stress and displacement of the corresponding cross section of six types of busts under different pressurized states. iii)Research on the change rule of pressure and displacement:according to the finite element simulation results,we analyzed the change rule of pressure and displacement under the difference of bust types.In addition,a functional relationship between pressure,displacement and angle at the bust section was constructed. The study shows that the stress at the BP point of the bust section is the largest under the external force,followed by the posterior lateral position,the curvature is larger and the position of the protruding place has a larger stress;with the gradual enlargement of the breast shape,the chest and the side of the human body have thickened the soft tissue layer,and the deformation of the body surface increases and shows a tendency to expand outward,but the largest position of the deformation is always in the vicinity of the BP point;the trigonometric function relationship between pressure,displacement and angle of the six kinds of breasts is constructed on the basis of the characteristics of breast type.The degree of fit(R2)is higher than 0.99,and the fitting effect is good.The surface deformation data of the bust section can be obtained from the measured point pressure of the bust section,which can simplify the measurement steps and replace the tedious measurement of the pressure displacement.This study can provide reference for the study of pressure comfort of tight-fitting garments.