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In this study, Sylgard 184 silicone rubber (SylSR) matrix composites with shear thickening fluid (STF) microcapsules (SylSR/STF) were fabricated. Their mechanical behaviors were characterized by dynamic thermo-mechanical analysis (DMA) and quasi-static compression. Their damping properties increased with the addition ofSTF into the SR in DMA tests and the SylSR/STF composites presented decreased stiffness and an obvious positive strain rate effect in the quasi-static compression test. Moreover, the impact resistance behavior of the SylSR/STF composites was tested by the drop hammer impact test. The addition of STF enhanced the impact protective performance of silicone rubber, and the impact resistance increased with the increase of STF content, which should be ascribed to the shear thickening and energy absorption of STF microcapsules in the composites. Meanwhile, in another matrix, hot vulcanized silicone rubber (HTVSR) with a mechanical strength higher than Sylgard 184, the impact resistance capacity of its composite with STF (HTVSR/STF) was also examined by the drop hammer impact test. It is interesting to note that the strength of the SR matrix obviously influenced the enhancement effect of STF on the impact resistance of SR. The stronger the strength of SR, the better the effect of STF on improving the impact protective performance of SR. This study not only provides a new method for packaging STF and improving the impact resistance behavior of SR, but is also beneficial for the design of STF-related protective functional materials and structures.

In order to obtain scaffold that can meet the therapeutic effect, researchers have carried out research on irregular porous structures. However, there are deficiencies in the design method of accurately controlling the apparent elastic modulus of the structure at present. Natural bone has a gradient porous structure. However, there are few studies on the mechanical property advantages of gradient bionic bone scaffold. In this paper, an improved method based on Voronoi-tessellation is proposed. The method can get controllable gradient scaffolds to fit the modulus of natural bone, and accurately control the apparent elastic modulus of porous structure, which is conducive to improving the stress shielding. To verify the designed structure can be fabricated by additive manufacturing, several designed models are obtained by SLM and EBM. Through finite element analysis (FEA), it is verified that the irregular porous structure based on Voronoi-tessellation is more stable than the traditional regular porous structure of the same structure volume, the same pore number and the same material. Furthermore, it is verified that the gradient irregular structure has a better stability than the non-gradient structure. An experiment is conducted successfully to verify the stability performance got by FEA. In addition, a dynamic impact FEA is also performed to simulate impact resistance. The result shows that the impact resistance of the regular porous structure, the irregular porous structure and the gradient irregular porous structure becomes better in turn. The mechanical property verification provides a theoretical basis for the structural design of gradient irregular porous bone tissue engineering scaffolds.

The polymeric materials in this study underwent mechanical tests (tensile test, impact resistance and hardness), which explained the use of polymeric materials in engineering and industrial applications that need good mechanical properties compared to metals, ceramic materials and woods, and this is a good thing because it is characterized by low cost and high efficiency with application performance In this study, the polycarbonate polymer was characterized by its high tensile strength in the event of breakage, but the elongation values decreased compared with the polypropylene and polyethylene polymers, which were characterized by high elongation at the expense of tensile strength, as the polycarbonate polymer acted as a brittle material as for resistance to shock, which reflected the amount of energy absorbed From the striking hammer, the impact resistance of high-density polyethylene increased compared to other polymers, as well as the hardness whose values were close to the three types of polymers used, which confirms the importance of these types in the application used in engineering.

Fiber-reinforced polymer (FRP) bars have better resistance to corrosion and higher tensile strength than steel bars, thus being a prospective material for concrete structures in marine engineering. However, it is less fire-resistant, and the residual bearing capacity of FRP-reinforced concrete members after the fire needs to be clarified. This study explores the impact resistance of Glass FRP-reinforced concrete (GFRP-RC) columns at high temperatures using finite element models. To assess the accuracy of the model, the simulation results were compared with the test results in terms of fire resistance and impact resistance, respectively. Based on these, the impact behavior of GFRP-RC and steel-RC columns were compared and analyzed. The results show that GFRP-RC columns were more severely damaged by impact loading after high temperatures than steel-RC columns. The peak impact forces of the GFRP-RC columns and steel-RC columns are nearly identical. However, the former has a smaller reaction force and a more significant mid-span displacement. Furthermore, the residual axial bearing capacity of GFRP-RC columns after high temperature and impact loading is significantly reduced compared to steel-RC columns. Exposure to high temperatures takes a more significant proportion in the reduction than impact loading. In addition, a relationship between the damage index (based on residual bearing capacity) and the lateral displacement of the columns after fire and impact loadings was established. In contrast, the corresponding damage classification criteria were determined.

This article provides an overview of the current development status of prestressed segmental precast and assembled piers, Emphasis was placed on analyzing the stress characteristics of bridge piers under impact. The concept of recoverable functional design and its application prospects were elaborated, and finally, the research on the impact resistance performance of prestressed segmental precast and assembled piers was discussed. Research has shown that optimizing design and material selection can effectively enhance the impact resistance and structural durability of bridge piers. At the same time, the introduction of the concept of recoverable functionality provides new ideas for the rapid repair and functional recovery of bridge piers, which helps to improve the recovery efficiency of bridges after extreme events. Future research should focus on the evaluation methods of impact resistance performance, new connection technologies, in-depth application of recoverable functional design, a combination of impact simulation experiments and numerical analysis, and exploration of comprehensive disaster prevention and reduction strategies. These research results will also promote the further development and innovation of prefabricated assembly technology in bridge engineering, bringing new ideas and methods to the field of engineering construction.

In order to meet the increasing application requirements with regards to structural impact resistance in industries such as mining, construction, aerospace engineering, and disaster relief and mitigation, this paper designs a variant truss beam structure with a large shrinkage ratio and high impact resistance. Based on the principle of the curved trajectory of scissor mechanisms, this paper conducts a finite element simulation analysis of the impact load on the truss beam structure, a theoretical analysis of the impact response and a relevant prototype bench-top experiment, completing a full study on the impact resistance mechanism of the designed variant truss beam structure under the impact load. In the paper, the buffer effect of the external load impact on the variant truss beam structure is analyzed from the perspective of the energy change of elastic–plastic deformation. This paper proposes an optimization strategy for the variant truss beam structure with the energy absorption rate as the optimization index through extensive analysis of the parameter response surfaces. The strategy integrates analyses on the response characteristic analysis of various configuration materials to obtain an optimal combination of component parameters that ensures that the strength of the truss beam structure meets set requirements. The strategy provides a feasible method with which to verify the effectiveness and impact resistance of a variant truss structure design.

This study investigates the mechanical performance of bio-inspired honeycomb sandwich structures under high-speed hail impacts. A detailed Ls-Dyna model was developed and validated using experimental results from hail impact tests on Carall composite structures from the literature, with the model’s accuracy confirmed through alignment of post-impact damage patterns, z-axis displacement values, and initial energy absorption with experimental data. Mesh refinement techniques, ranging from coarse to fine elements, were applied, revealing that smaller mesh sizes provided more detailed damage representation and improved accuracy in critical areas. Various impact angles (22.5°, 45°, 67.5°, and 90°) were analyzed to simulate real-world conditions, demonstrating that higher angles, particularly 90°, resulted in the most severe damage. Additionally, eight different honeycomb configurations, including hexagonal and bio-inspired designs, were incorporated into the sandwich structure model. The results showed that hexagonal, re-entrant, wavy, and SI honeycombs sustained substantial damage, while spider web, bamboo, pomelo peel, and grass stem designs exhibited superior resistance. Among all, the wavy honeycomb model achieved the highest specific energy absorption (sEA), showing a 5.62% improvement over the hexagonal model. This research underscores the potential of bio-inspired honeycomb structures in enhancing impact resistance, offering valuable insights for future design strategies in impact-critical applications.

In order to investigate the effectiveness of polymer modification and fiber reinforcement on the cracking and impact resistance of concrete materials prepared for ultra-thin whitetopping (UTW), carboxyl butyl benzene latex and polyformaldehyde fibers were added to the conventional cement concrete mix. In addition, test methods that used an asphalt mixture performance tester (AMPT) and mechanical rammer were developed to evaluate concrete cracking and impact resistance, respectively. Results from the AMPT test revealed that the cracking resistance can be enhanced with polymer and fiber, especially the initial tensile load peak, which can be improved by more than 40% when fiber and polymer compound modification is applied. Meanwhile, the impact loading test revealed that the inclusion of both fiber and polymer results in a two-fold increase in the number of impacts before visible cracking occurs, and the number of blows to failure increased by 21.4%. Moreover, microstructures were investigated by scanning electron microscopy (SEM) to confirm the reinforcing mechanism of both polymer modification and fiber reinforcement.

All-lightweight concrete (ALWC), using non-sintered fly ash ceramic pellets and pottery sand as coarse and fine aggregates, is a novel energy-efficient and environmentally friendly building material that has emerged in recent years. However, its structural behavior under impact loading remains to be thoroughly studied. This paper examines the dynamic response of four ALWC columns with different longitudinal reinforcement ratios and stirrup ratios under lateral impact loading using drop hammer tests. The effect of stirrup densification on the impact resistance was analyzed, focusing on the failure modes, impact forces, acceleration, and midspan displacement time history curves. Results showed that increasing the reinforcement and stirrup ratios shifted the column failure mode from shear to flexural failure, significantly enhancing peak impact force and reducing both midspan and residual displacements. Densifying the stirrups in the column ends resulted in localized flexural failure, with first and second peak forces increasing by 7.43% and 55.98%, respectively, thereby improving impact energy absorption and reducing impact damage.

Four samples, including homopolymerized PP (PP-1), random impact copolymerized PP (PP-2), random impact copolymerized PP of ethylene-propylene (PP-3), and random impact copolymerized PP of ethylene-propylene-butylene (PP-4), which were prepared by 75 KG Spheripol process pilot plant using ZN104M as catalyst, were adopted to study the structure and performance, i.e. , the influence of the different polypropylene molecular chain structures on the crystallization behavior of random impact copolymer polypropylene, and the changes in mechanical and optical performance due to the different aggregation structures of random impact copolymer polypropylene, and following results were achieved. Firstly, when ethylene-propylene rubber (EPR) and copolymerization monomers of ethylene and butylene were added in turn, the regularity of PP molecular chains decreased in different degree with the order of PP-1 > PP-2 > PP-3 > PP-4, and which further led to the same pattern for the crystallization peak temperature and the crystallinity. Secondly, half-crystallization time ( T 1/2 ) of the same cooling rate and the crystallization activation energy increased with the addition of EPR, ethylene and butylene. Crystallization activation energies were calculated to be 12.05 kJ mol −1 , 12.09 kJ mol −1 , 12.38 kJ mol −1 and 12.64 kJ mol −1 for PP-1, PP-2, PP-3 and PP-4, respectively. Last but the most importantly, the addition of EPR, ethylene and butylene would enhance the impact strength, but decrease the transmittance, whereas the haze changed little. Based on the theory between structure and performance, the reason that caused above results were analyzed. This work provided some guidance for the development of high-performance polypropylene used in identical fields.