Views: 29 Author: Site Editor Publish Time: 2025-11-24 Origin: Site
Technical Exploration: When the Force-Displacement Curve of Disc Spring Will Have a "Declining Section"?
In engineering applications of disc springs, the force-displacement (P-f) curve morphology is central to their design. While most springs exhibit linear or gradually increasing characteristics, disc springs uniquely demonstrate a "descending segment" – a negative stiffness feature. Leveraging its profound expertise in disc spring technology, Jiangsu Sunzo Spring will analyze the underlying mathematical principles and design essentials behind this phenomenon.
The force-displacement relation of a single-disc spring is essentially a cubic function. The existence of a descending segment of the curve depends on the ratio of the free height (h₀) to the thickness (t), i.e. the section coefficient h₀/t.
Through theoretical deduction and calculation, a clear conclusion can be drawn:
When the ratio of h₀ / t is greater than √2 (approximate to 1.414), the force-displacement curve will have a descending segment.
In the descending region of the curve, the spring exhibits a "negative stiffness" property: the reaction force provided by the spring decreases as the deformation increases. This is a very unique and useful mechanical behavior.
Understanding and controlling this characteristic is the embodiment of high level disc spring design.
Design warning: For the conventional application which needs stable stiffness, the design should avoid making the disc spring work in this range, so as to prevent the system from losing stability.
Innovation Application: On the contrary, this characteristic can be cleverly used in the vibration isolation system. By using the negative stiffness region, the support system with very low stiffness can be constructed to realize the efficient isolation of the vibration of a specific frequency.
At Jiangsu Sunzo Spring, our disc spring technical services go beyond delivering premium products compliant with the National Standard for Disc Springs. We are committed to comprehensively understanding the entire value chain, from mathematical principles to product performance. Whether you need to avoid negative stiffness zones for stability or leverage this characteristic for innovative designs, our technical team provides professional theoretical support and tailored solutions.
By predicting and controlling the characteristic curve of disc springs, we help your products achieve enhanced performance and reliability.
SUNZO has it’s own researching and development team and test center, has participate in rule-making of the latest national industry standards and the international ISO standards for disc springs.
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