Systems and Methods of Numerically Simulating Structural Behaviors of Airbag Made of Coated Fabric Material

A system for numerically simulating structural behaviors of an airbag made of coated fabric material comprising:

• a main memory for storing computer readable code for a finite element analysis application module;
• at least one processor coupled to the main memory, said at least one processor executing the computer readable code in the main memory to cause the finite element analysis application module to perform operations by a method of:
• obtaining simulated structural behaviors of the airbag by conducting a time-marching simulation using the finite element model in the computer system, said time-marching simulation containing a number of solution cycles with each solution cycle representing a particular time of the time-marching simulation;
• and
• at said each solution cycle, deriving a pair of slave elements located at either side of each membrane element by updating nodal locations of the slave elements, the slave elements possessing same number of nodes of said each membrane element, the respective nodal locations being offset by a distance from corresponding nodes of said each membrane element along a direction defined by average nodal normal vector, said distance being calculated from the fabric thickness and the coating thickness, said average nodal normal vector of a particular node being calculated by averaging element normal vector of those membrane elements connected to the particular node, and then obtaining additional bending resistance of said each membrane element by transforming an internal force calculated from strains and stresses of the respective slave elements through the updated nodal locations.

A non-transitory computer readable storage medium containing instructions, when executed in a computer system, for numerically simulating structural behaviors of an airbag made of coated fabric material by a method comprising:

• receiving, in a computer system having a finite element analysis application module installed thereon, a finite element model containing a plurality of membrane elements representing an airbag made of coated fabric material and receiving coating thickness and fabric thickness of the coated fabric material;
• obtaining simulated structural behaviors of the airbag by conducting a time-marching simulation using the finite element model in the computer system, said time-marching simulation containing a number of solution cycles with each solution cycle representing a particular time of the time-marching simulation;
• and
• at said each solution cycle, deriving a pair of slave elements located at either side of each membrane element by updating nodal locations of the slave elements, the slave elements possessing same number of nodes of said each membrane element, the respective nodal locations being offset by a distance from corresponding nodes of said each membrane element along a direction defined by average nodal normal vector, said distance being calculated from the fabric thickness and the coating thickness, said average nodal normal vector of a particular node being calculated by averaging element normal vector of those membrane elements connected to the particular node, and then obtaining additional bending resistance of said each membrane element by transforming an internal force calculated from strains and stresses of the respective slave elements through the updated nodal locations.