Techno Press
Techno Press

Steel and Composite Structures
  Volume 59, Number 2, April 25 2026 , pages 181-208
DOI: https://doi.org/10.12989/scs.2026.59.2.181
 


Low-velocity impact response of polyurea-coated steel tubes: A numerical study on deformation and coating effectiveness
Shiqi Zhao, Peng Deng, Jiacheng Liu, Jian Guo, Zhongyi Zhu

 
Abstract
    This study numerically investigates the impact resistance of circular steel tubes coated with polyurea elastomer under low-velocity drop-weight impact. A total of 144 finite element (FE) models of composite tubes and 24 uncoated steel tubes were established to systematically analyze the effects of polyurea thickness, spray position, length-to-diameter ratio (α), diameter-to-thickness ratio (γ), and impact energy (Eₐ). The failure modes are classified into three types: local denting (L), global bending (G), and coupled deformation. The latter refers to a combination of L and G, further distinguished as “L+G” (local denting dominant) or “G+L” (global bending dominant) based on which component contributes more to the total displacement. This method was developed using a modified equal-area axis method combined with bottom bending angles. Results demonstrate that double-sided polyurea coatings (4 mm thickness) most effectively suppress radial bulging and enhance energy absorption, particularly under high-energy impacts (Eₐ ≤ 11.2 kJ). The Discussion section validates failure modes in bare steel tubes using the P₀/λPₓ ratio and proposes a new dimensionless criterion incorporating coating parameters to accurately predict failure modes in composite tubes. The parametric analysis provides fundamental insights for optimizing polyurea reinforcement strategies in industrial pipelines susceptible to accidental impact.
 
Key Words
    circular steel tube; impact resistance; low-velocity impact; numerical simulation; polyurea elastomer
 
Address
Shiqi Zhao:College of Civil Engineering and Architecture, Shandong University of Science and Technology,
Qingdao 266590, China

Peng Deng:1)College of Civil Engineering and Architecture, Shandong University of Science and Technology,
Qingdao 266590, China
2)Shandong Provincial Key Laboratory of Civil Engineering Disaster Prevention and Mitigation, Shandong
University of Science and Technology, Qingdao 266590, China

Jiacheng Liu:College of Civil Engineering and Architecture, Shandong University of Science and Technology,
Qingdao 266590, China

Jian Guo:College of Civil Engineering and Architecture, Shandong University of Science and Technology,
Qingdao 266590, China

Zhongyi Zhu:College of Civil Engineering and Architecture, Shandong University of Science and Technology,
Qingdao 266590, China
 

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