# Design and Simulation Analysis of a New Type of Assembled UHPC Collision Avoidance
## 6 Conclusions  
The performance of the new type of assembled UHPC collision avoidance device is analyzed by the finite element numerical simulation method. The following conclusions are drawn:  
1. The new type of assembled UHPC collision avoidance device proposed in this paper consists of three types of modular collision avoidance floating boxes and intermittent rubber sliders. Each collision avoidance floating box is composed of rubber drums, rubber damper material, a double-layer, double-direction, densely reinforced, and super high-performance concrete shell structure, and steel supporting elements. This device can take full advantage of its plastic deformation, strong energy absorption, excellent corrosion resistance and durability, modular production and assembly, high efficiency of on-site installation, convenient replacement of damaged floating boxes, and low maintenance cost. 2. The newly assembled UHPC collision avoidance device can significantly reduce the maximum impact force and extend the impact duration of the pier in a ship-bridge collision. For the forward collision conditions, which occur frequently and result in serious damage in engineering practice, the peak impact force acting on the pier can be reduced by 41.8%, the impact duration can be extended by 100.0%, and the damage deformation energy to the bow can be reduced by 34.6%. The collision avoidance device can protect bridge piers and ships efficiently. 3. The damage to and deformation of the collision avoidance device itself is mainly concentrated in any of the floating boxes directly impacted by the ship, the rubber drums on the external side of the floating boxes, and the rubber sliders on the internal side. The other, not directly impacted, floating boxes will not undergo damage or deformation. 4. The new collision avoidance device has good collision avoidance and energy dissipation performance, which mainly comes from the UHPC floating boxes that have double-layer two-way dense reinforcement and the internal steel supporting elements. The floating box wall can take full advantage of its strength to improve the overall strength of the device. The internal supporting elements fully absorb the impact kinetic energy by elastic-plastic deformation and buckling. The discontinuous rubber sliders on the internal side of the collision avoidance device can improve the hard contact environment between the device and the pier, and significantly reduce the peak impact force of the pier. 5. Because of its reasonable design and layout, the internal steel support has a high flexibility and viscous energy dissipation response during the impact process of 5000 DWT ships, so it can be used as a flexible energy dissipation and impact resistance component, especially under impact conditions, and has good economic application prospects. Only finite element results are presented in this paper. The results are to be confirmed by experimental investigation. Conceptualization, L.Z., H.L., J.W., X.P., A.D.M. and L.J. ; methodology, L.Z., H.L. and X.P. ; software, L.Z., H.L., J.W., X.P., A.D.M., L.J. ; validation, L.Z., H.L. and X.P. ; formal analysis, [PERSON], [PERSON], [PERSON], X.P. and D.H.; investigation, [PERSON], [PERSON], J.W., X.P. and D.H.; resources, [PERSON], [PERSON], X.P., A.D.M. and L.J. ; data curation,L.Z., H.L., J.W., X.P., A.D.M., L.J. and D.H.; writing--original draft preparation, [PERSON], [PERSON], J.W., X.P., A.D.M. and L.J. ; writing--review and editing, [PERSON], H.L. and J.W. ; supervision, [PERSON], [PERSON], [PERSON], X.P., A.D.M. and L.J. ; project administration, [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON] and [PERSON]; funding acquisition, [PERSON], [PERSON], [PERSON], [PERSON], A.D.M. All authors have read and agreed to the published version of the manuscript.