Through biological evolution, bivalve mollusks developed shells to improve the utilization of metabolic energy and provide protection against external threats. In addition to the mechanical optimization of the microstructure, the design of the macroscopic shape of a bivalve shell naturally becomes a potential approach to achieving the aforementioned purposes. While the functions of some features of mollusk shells have been studied, the role of the suture-serrate margins, a common morphology of bivalve shell edges, in the global mechanical behaviors of bivalve shells requires further exploration. Here, we present how the serrate margins contribute to the global mechanical properties of bivalve shells. The results of the compression tests employed on a typical bivalve, M. mercenaria, showed that the complete bivalve shells with suture-serrate margins perform better in terms of strength and work to fracture than those without the margins under the same conditions (dry and wet). The primary failure types observed during compression reveal that the failure mechanisms of valve shells are dependent on the suture-serrate margin morphology and water content. Using numerical simulations, the mechanical functions of the suture-serrate margins were demonstrated. Specifically, serrate margins provide mutual resistance by “locking” complementary valves to redistribute and eliminate stress concentrations around pre-existing defects, thereby enhancing the mechanostability and strength of the entire structure.

通过生物进化，双壳软体动物开发了壳，以改善代谢能的利用并提供抵御外部威胁的保护。除了微观结构的机械优化之外，双瓣壳的宏观形状的设计自然成为实现上述目的的潜在方法。尽管已经研究了软体动物壳的某些特征的功能，但双壳贝壳的整体力学行为中的缝线锯齿状边缘（双壳贝壳边缘的常见形态）的作用尚待进一步探索。在这里，我们介绍锯齿状边距如何对双瓣壳的整体机械性能做出贡献。在典型的双壳类M. mercenaria上进行的压缩测试的结果的研究表明，在相同条件下（干湿），具有缝合线锯齿状边缘的完整双壳贝壳在强度和断裂功方面要优于没有边缘的贝壳。在压缩过程中观察到的主要失效类型表明，阀壳的失效机理取决于缝线锯齿状边缘形态和含水量。使用数值模拟，证明了缝线锯齿状边缘的机械功能。具体地说，锯齿状边缘通过“锁定”互补阀提供了相互抵抗，从而重新分布并消除了预先存在的缺陷周围的应力集中，从而增强了整个结构的机械加工性和强度。