Abstract: Based on the background that the majority of the population spends more time in a seated position and the demand for cushion products is increasing, the selection of cushion products with a high level of comfort has become the focus of consumer attention. In this paper, for the 50th percentile male representative group in China, three kinds of materials, namely warp-knitted spacer fabrics, sponges with a medium density of 28 kg/cm³, and sponges with a high density of 50 kg/cm³ were selected as the filler of cushion products to obtain three kinds of cushion materials.
We explored the mechanical characteristics of the three types of materials and the methodology and effectiveness of finite element simulation, and established relevant material microelement models to assist design prediction. The results show that the intrinsic model with the highest compression-strain fit (99.24%) among sponges with a medium density of 28 kg/cm³, sponges with a high density of 50 kg/cm³ and warp-knitted spacer fabrics is LOW DENSITY FOAM. Meanwhile, the mathematical model of the relationship between deformation of warp-knitted spacer fabrics and the amount of compression force applied, as well as the thickness of the material was obtained by using the quadratic polynomial surface fitting of MATLAB.
Subsequently, the process of contact between human body and three different cushion products in sitting posture was simulated by finite element simulation in ABAQUS software to analyze the comfort of the products according to the distribution of body pressure on the cushion surface, and the validity of the simulation experiments was verified by using a body pressure tester. It is found that the peak value of the elastic cushion surface of the warp-knitted spacer fabric is larger than that of the elastic cushion surface of sponges with a medium density of 28 kg/cm³, and smaller than that of the elastic cushion surface of sponges with a high density of 50 kg/cm³, and the distribution of the overall cushion surface is more homogeneous than that of the sponge cushion; and the body pressure tester verifies that the simulation data are less than 5% of the actual test data, which proves the feasibility of the simulation experiment.
Warp-knitted spacer fabrics exhibit better support and breathability than sponge materials. Combined with the results of objective data analysis, it is believed that as these materials continue to evolve, they can provide more choices for future elastic cushion products.

Key words: warp-knitted spacer fabric, finite element, mechanical properties, constitutive model, pressure distribution, micro-element deformation

摘要： 将经编间隔织物和不同密度的海绵材料作为坐垫的填充物，通过分析坐垫上的人体体压分布情况，深入探讨坐垫的整体舒适度。首先，选择中密度海绵（28 kg/cm³）、高密度海绵（50 kg/cm³）及新型弹性材料经编间隔织物，对其进行力学性能进行实验。随后，采用有限元仿真法，对三种材料分别进行单轴压缩仿真，分析得出拟合度最高的本构模型；对经编间隔织物材料进行微元变形仿真，分析该材料变形量、压强、厚度三者关系的数学模型。最后，建立弹性坐垫和中国50百分位男性的人体臀部（软组织+骨骼）仿真复合模型，分析臀部与垫面的体压分布数据，并利用体压测试仪验证仿真数据的有效性。结果发现：中密度海绵、高密度海绵及经编间隔织物在仿真分析后体压-应变拟合度最高（为99.24%）的本构模型选低密度泡沫较合适；可经过MATLAB进行二次多项式拟合得出经编间隔织物的变形量、压强、厚度三者之间的数学模型；经编间隔织物弹性坐垫垫面的峰值比中密度海绵弹性坐垫垫面的体压峰值大，比高密度海绵弹性坐垫垫面的体压峰值小，整体垫面体压分布情况较海绵坐垫更均匀；体压测试仪验证仿真数据与实际测试数据小于5%，表明仿真实验的可行性。研究表明，经编间隔织物比海绵材料具有更好的支撑性和压力舒适性。这些实验结果的数据以及虚实结合的方法可为未来弹性坐垫产品的材料选择及开发模式提供参考。

关键词: 经编间隔织物, 有限元, 力学性能, 本构模型, 体压分布, 微元变形