The Y-shaped rubber seal ring is mainly used for sealing the piston, injection plug and piston rod in the dry hydraulic system. In order to obtain the initial seal, the Y-ring seal is designed with a certain amount of interference between the inner and outer lips. The sealing effect is achieved when the sealing ring is mounted in the groove. Under pressure, a contact pressure is generated as the sealing lip deforms in the circumferential direction. With the increase of liquid pressure, the deformation and contact pressure also increase, and the Y-ring achieves the effect of self-sealing... When the author develops a new type of non-rigid connection connector for oil pipelines, a Y-shaped rubber sealing ring (non-standard piece) is designed as the seal of the connector, and the required sealing state is static seal. In order to verify its performance, the traditional method is to develop a physical rubber ring to test and study whether its sealing performance meets the requirements. This method is time-consuming, laborious and inefficient. In order to improve design efficiency and save research costs, the author proposes to use large-scale finite element analysis software AN-SYS to carry out finite element analysis on the design of Y-shaped sealing ring, and to study its sealing performance through analysis. The stress, contact pressure and deformation of the sealing ring.

1. Finite element analysis model of Y-shaped sealing ring

Stress-strain relationship of 1.1 rubber materials

Rubber is essentially a viscoelastic material, and its mechanical properties are related to time and temperature, that is, it shows creep, relaxation, aging and other phenomena. However, when the time is short and the temperature does not change much, it can be considered that the rubber material is completely elastic, that is, after the load is removed, the rubber material is completely restored to the undeformed state. In the sealing structure, its mechanical model is characterized by complex material nonlinearity and geometric nonlinearity.

AN-SYS nonlinear hyperelastic models include PolynomidForm model, Mooney.Rivlin model, Neo-Hookean model, Yeoh model, Arruda-Boyce model, Gent model, Ogden model, Hyperfoam model, Blatz.Ko model old 1. Currently in ANSYS Medium and Wide

The Mooney-Rivlin model is used to describe the strain energy function of rubber materials.

(1) where: w is the modified strain energy, c. is the Rivlin coefficient, and l and 2 are the first and second Green's strain invariants, respectively.

When the author of this article uses ANSYS for finite element analysis, using the Mooney.Rivlin model with two constants, formula (1) becomes:

(2) where: c .. and c0. The Rivlin coefficients are all positive definite constants.

Finite Element Analysis of 1.2 Contact Problems

The complexity of the contact problem Ho is caused by the change of the state of the system, that is, the contact and separation between objects, so the contact problem is also called the state nonlinear problem. At present, scholars from various countries have proposed a variety of finite element algorithms for contact problems, such as Lagrange multiplier method, penalty meta-method, solver-based direct constraint method and so on. The author of this paper adopts the penalty meta-method. The penalty element method is to establish false.