Finite-element simulation of pressure profile and 3D deformation of breasts wearing adjustable bras

Adjustable bras should be well designed with scientific analysis of pressure distribution to maintain a balance between the multidimensional considerations of comfort, function, and safety. A contact mechanics model of a body-adjustable brassiere was developed, with the aim of investigating the interaction between these considerations, and of further scientifically optimizing the pattern design and fabric selection. Point cloud data were obtained through 3D body scanning, and the torso surface was reconstructed using a detection contour method. A geometric model of the torso was divided into soft tissue, thorax, and breast by reverse engineering; the brassiere geometric model, in the semi-dressed state, was divided into eight parts and constructed using forward–reverse methods. The breast and soft tissue were considered as linear elastic entities with different material parameters, the thorax was taken to be a rigid body, and the brassiere was modeled as a linear elastic shell with variable components and material parameters. The simulation was validated by pressure measurement and shaping evaluation in vivo. Results show that the model could be used to predict the contact pressure and 3D deformation with reasonable accuracy. The contact pressure at the top of the shoulder is 4.9–7.8 kPa, that at the underband is 1.9–4.9 kPa, and that at the upper band is 1.0–2.9 kPa. The pressure on the breasts is mainly concentrated in the lower half of the breasts, and ranges from 0.1 to 1.5 kPa. The finite-element model developed in this study helps to provide a better understanding of the complex interactions between the body and an adjustable brassiere, and can be used to analyze different bra design features (fabric parameter, pattern, etc.) for predicting the pressure distribution and deformation of breast shapes.