Disc spring stress analysis guide: The key to accurate design

In the design and application of disc springs, "stress" serves as the core physical parameter for evaluating their performance and reliability. Simply put, stress refers to the internal force generated by an object to resist external forces. For disc springs, precise stress calculation and control directly determine the product's fatigue life and load-bearing capacity. Leveraging Jiangsu Sunzo spring's extensive technical expertise in disc spring development, we provide an in-depth analysis of stress distribution mechanisms and key design considerations within these components. 

1、Recognize the five key stress points of the disc spring

The stress distribution of disc springs is extremely complex. The national standard and industry practice usually use the stress of σⅠ, σⅡ, σⅢ, σⅣ, σOM five key points to characterize its mechanical state. Understanding these stress points is the basis for scientific disc spring design.

σOM: Core stress of the central layer

This represents the stress at the upper surface OM of the central point in the central layer of the disc spring. It is one of the core control indicators in the design and selection of disc springs. Under static or small cyclic loads, the allowable value is typically designed between 1400 and 1600 MPa.

σⅠ: Tensile stress on the upper edge of the inner diameter

This represents the stress at the upper edge of the inner circumference of the disc spring, primarily manifested as tensile stress. In design, this value is typically required to be ≤ 3000 MPa, which is the key control point to prevent brittle fracture of the material.

σⅡ and σⅢ: critical stress for fatigue life

For disc springs subjected to dynamic loads (alternating loads), the control of these two stress points is crucial, which directly determines the fatigue life of disc springs.

σII (inner diameter lower edge stress) should not exceed 1300 MPa.

σIII (lower edge stress of outer diameter) should not exceed 1200 MPa.

Strictly controlling these two stresses within the allowable range is the premise to ensure high fatigue life.

σⅣ: Upper edge stress of outer diameter

This point stress is usually low and generally does not cause disc spring failure. In conventional design, it is not used as the main control object.

2、Meaning of stress unit: MPa

MPa is a common unit of stress (pressure), 1 MPa = 1 N/mm⊃2;. This unit intuitively reflects the magnitude of force on a unit area, which is the basis for strength calculation.

3、The practice of threefold flexibility: Let stress calculation serve reliable design

At Jiangsu Sunzo spring, our disc spring design goes far beyond basic formulas. Through advanced mechanical models and extensive practical experience, we precisely simulate and optimize the stress distribution of each disc spring under various operating conditions. We deeply understand:

For static loads, σOM and σⅠ should be prioritized for control to ensure their static strength safety.

For dynamic fatigue load, σⅡ and σⅢ must be strictly controlled below the allowable standard to greatly improve the service life of the product.

If you have any questions about the stress analysis, life estimation or selection of disc spring under specific working conditions, we are willing to provide a solid guarantee for the reliability of your equipment with our professional technical ability.