Impact Force when Fabric Inflates at High Speed

Occupant protection systems for automobiles are currently highly publicized. An airbag inflating at high speed impacts an occupant with great force. Airbag safety relies on its construction with primarily woven fabrics. We have referred to a typical pressure-time history of an airbag and developed a device to measure impact load when the fabric airbag inflates at high speed. When interior pressure in the airbag increased, impact load increased. Also, the impact load on a body increased as the distance between the body and airbag decreased. The impact force of an airbag inflating at high speed was simulated by a non-linear finite element method (FEM) combined with an incremental method, where the sample was modeled by a thin elastic shell. An experiment was conducted to verify the theory and this calculation method. Good agreement was obtained between the theoretical and experimental values for two types of fabric sample. This demonstrated that the mathematical technique developed here can satisfactorily predict the impact force when an airbag inflates at high speed and that the impact force depends appreciably on the mechanical properties of fabrics.ArticleTEXTILE RESEARCH JOURNAL. 79(9):837-843 (2009)journal articl

Friction characteristics of fabrics in the presence of air

High frictional force between the skin and the air bag greatly influences the scratch damage to human skin when an air bag inflates and rubs against the skin. The coefficient of friction should therefore be reduced. In this study, we propose a new method to reduce frictional force by producing air lubrication between an air bag made of a non-coated fabric and the human skin. Air was generated, and an experimental device that could measure frictional force was produced. The frictional force of the air bag with air was measured, and the effectiveness and efficiency were confirmed. In the presence of air, the friction disk materials, fabric materials, and fabric structure do not influence the frictional force and coefficient of friction. Instead, the coefficient of friction is influenced by air mass flow passing through the fabric.ArticleJOURNAL OF THE TEXTILE INSTITUTE. 102(7):598-603 (2011)journal articl

Reusing recycled fibers in high-value fiber-reinforced polymer composites: Improving bending strength by surface cleaning

Glass fiber-reinforced polymer (GFRP) composites and carbon fiber-reinforced polymer (CFRP) composites were recycled using superheated steam. Recycled glass fibers (R-GFs) and recycled carbon fibers (R-CFs) were surface treated for reuse as fiber-reinforced polymer (FRP) composites. Treated R-GFs (TR-GFs) and treated R-CFs (TR-CFs) were characterized by scanning electron microscopy (SEM) and remanufactured by vacuum-assisted resin transfer molding (VARTM). Most residual resin impurities were removed by surface treatment. Analysis indicated no adverse effect of surface treatment on bending strength. The mechanical properties of the TR-GF reinforced polymer (TR-GFRP) and TR-CF reinforced polymer (TR-CFRP) composites were determined and compared with those of R-GF reinforced polymer (R-GFRP) and R-CF reinforced polymer (R-CFRP). The bending strengths of R-GFRP (26%) and R-CFRP (49%) were very low, compared to that of virgin glass fiber-reinforced polymer (V-GFRP) and that of virgin carbon fiber-reinforced polymer (V-CFRP). The bending strength of TR-GFRP composites was improved to about 90% of that of V-GFRP, and the bending strength of TR-CFRP composites was improved to about 80% of that of V-CFRP.ArticleCOMPOSITES SCIENCE AND TECHNOLOGY. 72(11):1298-1303 (2012)journal articl

Measurement and evaluation methods for damage of fibers from dry sand erosion in a hot environment

Bag filters composed of fibrous components are widely used to clean exhaust gas. It is reported that filter damage during dust collection involves erosion wear caused by particle collision. Thus, it is necessary to determine the life of bag filters in a hot environment and to clarify the erosion mechanism of fibrous materials. Experiments and evaluation methods were developed to investigate the erosion of fiber at high temperatures. The experiments involved reproducing the erosion of fibrous materials in various temperatures. Analysis of the relationship between the erosion damage rate of a specimen and the total kinetic energy of particles before colliding indicates the erosion resistance of fibrous materials at various temperatures. Using the suggested damage energy curve, we can evaluate the erosion wear characteristics of fiber under different experimental conditions.ArticleTEXTILE RESEARCH JOURNAL. 82(15):1612-1617 (2012)journal articl

Friction characteristics of fabrics in the presence of air

High frictional force between the skin and the air bag greatly influences the scratch damage to human skin when an air bag inflates and rubs against the skin. The coefficient of friction should therefore be reduced. In this study, we propose a new method to reduce frictional force by producing air lubrication between an air bag made of a non-coated fabric and the human skin. Air was generated, and an experimental device that could measure frictional force was produced. The frictional force of the air bag with air was measured, and the effectiveness and efficiency were confirmed. In the presence of air, the friction disk materials, fabric materials, and fabric structure do not influence the frictional force and coefficient of friction. Instead, the coefficient of friction is influenced by air mass flow passing through the fabric.ArticleJOURNAL OF THE TEXTILE INSTITUTE. 102(7):598-603 (2011)journal articl