Foam material is one of the ingredients that are frequently used for controlling of touch feeling on the contacting part of various products like bed mattresses. For better sleep, it is necessary to design to control the touch feeling of the mattresses. Touch feeling depends on various properties of the foam material, and the shape characteristics of the contact part also give humans various and complicated feelings. According to previous studies, it was possible to easily quantify the physical properties of foam materials by using indentation test. Furthermore, it is necessary to analyze the change in touch feeling due to the shape of contact part of foams for better mattress design. Then, the purpose of this study is to evaluate the touch feeling with multiple shape parameters of foam surface on the contacting point. Here, this become the contact problem between the foam material with the shape change and the human body which is modelled by simplicial ball in the first step of this study. The contact problem is modelled by unit cells in FEM. By thinking for periodic unit cell, it is mathematically approximated to push the foam uniformly as the curvature of the contact surface is large. FE model was developed by approximating the unit cells. Using the analysis model, vertical compress analysis by rigid plate was performed to get the relationship between displacement and reaction force.　 The result is the reaction force behavior of the entire contact surface with the human body. For this purpose, all the reaction forces for the indentation amount at each point were added. As a result, the reaction force behavior of the human body with respect to the pushing amount can be understood. In this study, it was assumed that the human body was pushed in the hip. Then, it is the reaction force behavior was analyzed for the design. The result was made a new softness parameter. From the behavior of the parameters, it was found that peaks occur at the beginning of pushing by causing the tip shape even in the same material. Then, the push stroke until the peak occurs is shortened as the tip shape is pointed. The maximum value of the peak becomes larger as the tip shape becomes sharper. The click ratio can be calculated from the maximum and minimum values of the peak. It was found that the click ratio increased by making the tip shape take.


Computational Design Method to Control Touch Feeling of Mattress With Geometric Surface-Shape

Division / Sponsors: 
Aerospace, Bioengineering, Applied Mechanics, Design Engineering Division, Advanced Energy Systems, Manufacturing Engineering Division, Noise Control and Acoustics, Nondestructive Evaluation, Diagnosis, and Prognosis (NDPD), Nuclear Engineering Division, Process Industries Division, Fluids Engineering, Heat Transfer, Materials, Microelectromechanical Systems, Safety Engineering and Risk Analysis, Computers & Information in Engineering


Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2020/volume/84478

IMECE2020 - Virtual Conference

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.