基于蜂窝结构的软组织力学模型

MECHANICAL MODEL OF SOFT TISSUES BASED ON HONEYCOMB STRUCTURE

  • 摘要: 在介入手术中,针具与软组织之间的相互作用会引起软组织大变形,导致病灶位置偏移,从而影响手术精度。建立准确的软组织形变模型,对于实现病灶点的术前预测或术中主动操控具有关键的理论意义。该文提出采用蜂窝结构来表征软组织的力学性能与形变行为。构建了一种可用于表征软组织的蜂窝单胞模型,阐述了其几何构成与拓扑形式。基于欧拉-伯努利梁理论,综合运用力法正则方程、莫尔积分及能量法,推导了该蜂窝单胞在压缩载荷下的位移解析表达式与等效弹性模量等数学模型,并通过有限元仿真验证了理论模型的正确性。通过材料压缩实验,获得了与仿生软组织力学性能相匹配的理想蜂窝单胞结构参数,据此建立了能够有效描述软组织力学特性与形变行为的蜂窝结构形变模型。

     

    Abstract: During interventional procedures, the interaction between surgical needles and soft tissues induces substantial deformation of the soft tissues, leading to displacement of the target lesions and consequently compromising procedural accuracy. Developing a precise soft tissue deformation model is of critical theoretical importance for preoperative prediction or intraoperative manipulation of lesion sites. This paper innovatively proposes the use of a honeycomb structure to characterize the mechanical properties and deformation behavior of soft tissues. A honeycomb unit cell suitable for representing soft tissues is constructed, and its geometric composition and topological configuration are elaborated. Based on Euler-Bernoulli beam theory and by integrating the force method regularization, Mohr’s integral, and the energy approach, the analytical expressions for displacement and the equivalent Young’s modulus of the unit cell under compressive loading are derived. The theoretical model is further validated through finite element simulations. Via material compression experiments on biomimetic soft tissues, an ideal honeycomb cell with matching mechanical properties is identified, thereby establishing a honeycomb-based deformation model capable of effectively describing the mechanical characteristics and deformation behavior of soft tissues.

     

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