【新文速递】2024年12月17日固体力学SCI期刊最新文章

今日更新：Composite Structures 8 篇，Composites Part A: Applied Science and Manufacturing 1 篇，Composites Part B: Engineering 1 篇，Composites Science and Technology 2 篇Composite StructuresCompressibility and meso-mechanical behavior of polymer bonded explosives with different crystal qualities during pressing processYuchen Guo, Pengwan Chen, RuiLiu, ZhijianYang, Feng Zhang, Liyang Feng, Kezhen Lv, Bo Zhou, Gaoyang Hudoi:10.1016/j.compstruct.2024.118784不同结晶质量聚合物粘结炸药在压制过程中的压缩性和细观力学行为As the predominant component in polymer bonded explosives (PBX), explosive crystals is an important factor affecting the compressibility of PBX powder. To obtain the effects of crystal quality on the mechanical properties and meso-mechanical behavior of PBX powder during die pressing, the compaction density, Brazilian strength, as well as crack propagation and energy dissipation mechanisms were systematically studied based on experiments and Discrete Element Method (DEM) simulations. The experimental results revealed that, under identical pressure, PBX parts composed of 1,3,5,7-tetranitro-1,3,5,7-tetraazecycloctane (HMX) crystals with more internal defects and lower strength will exhibit higher density and Brazilian strength. The simulation results demonstrated that crystal fragmentation occurs throughout the pressing process. The increased Brazilian strength of PBX containing low quality crystals may be attributed to more defects and larger specific surface area of the crystals. Crystal fragmentation can effectively promote particle rearrangement, resulting in higher strain of the PBX powder. During the compression process, the lower the crystal quality, the greater their susceptibility to fracture and the reduced conversion of external work into elastic potential energy. Consequently, the increase in PBX size caused by the release of elastic potential energy after unloading is therefore minimized, resulting in improved compressibility of the PBX.炸药晶体作为聚合物粘结炸药的主要成分，是影响聚合物粘结炸药粉末可压缩性的重要因素。为了获得晶体质量对PBX粉末在模压过程中力学性能和细观力学行为的影响，基于实验和离散元法（DEM）模拟，系统研究了压实密度、巴西强度、裂纹扩展和能量耗散机制。实验结果表明，在相同压力下，由内部缺陷较多、强度较低的1,3,5,7-四氮杂环辛烷（HMX）晶体组成的PBX部件具有较高的密度和巴西强度。模拟结果表明，在挤压过程中，晶体破碎现象不断发生。含有低质量晶体的PBX的巴西强度增加可能是由于晶体的缺陷较多，比表面积较大。晶体破碎可以有效地促进颗粒重排，从而提高PBX粉末的应变。在压缩过程中，晶体质量越低，其断裂易感性越大，外部功转化为弹性势能的量也越少。因此，卸荷后因释放弹性势能而导致的PBX尺寸增加被最小化，从而提高了PBX的可压缩性。Experimental study on GFRP spiral-confined concrete under eccentric compressionX.B. Hu, X.F. Nie, J.J. Wang, T. Yu, S.S. Zhangdoi:10.1016/j.compstruct.2024.118793GFRP螺旋约束混凝土偏心受压试验研究Fiber-reinforced polymer (FRP) composites are increasingly being employed as internal reinforcement in concrete structures due to their superior mechanical properties and excellent durability. The use of FRP spirals as internal shear reinforcement in compressive concrete members can also provide significant confinement to concrete and thus improve the compressive performance of the concrete members. Compared with studies on the behavior of FRP spiral-confined concrete (FSCC) under concentric compression, the existing studies on FSCC under eccentric compression have been very limited. In the present study, therefore, an experimental program containing 30 specimens was designed and conducted to investigate the compressive behavior of glass FRP (GFRP) spiral-confined concrete (GSCC) under eccentric compression, with the main examined parameters including the FRP spiral pitch and the load eccentricity-to-diameter ratio. The test results revealed that load eccentricity could largely influence the behavior of GSCC in terms of compressive strength, stiffness, ultimate axial deformation and ultimate section curvature. On the other hand, the decrease in the FRP spiral pitch can to some extent compensate for the influence of load eccentricity. The present study sets a solid experimental basis for the future numerical and theoretical studies on the behavior of GSCC under eccentric compression.纤维增强聚合物（FRP）复合材料由于其优异的力学性能和耐久性，越来越多地被用于混凝土结构的内部加固。在受压混凝土构件中使用FRP螺旋作为内剪钢筋也可以对混凝土提供显著的约束，从而提高混凝土构件的抗压性能。与对FRP螺旋约束混凝土（FSCC）在同心压缩下的性能研究相比，现有的FSCC在偏心压缩下的研究非常有限。为此，设计了包含30个试件的试验方案，研究了玻璃玻璃钢（GFRP）螺旋约束混凝土（GSCC）在偏心受压下的抗压性能，主要考察参数包括玻璃钢螺旋节距和荷载偏心径比。试验结果表明，载荷偏心对GSCC的抗压强度、刚度、极限轴向变形和极限截面曲率的影响较大。另一方面，FRP螺旋节距的减小可以在一定程度上补偿载荷偏心的影响。本文的研究为今后GSCC偏心受压特性的数值和理论研究奠定了坚实的实验基础。Broadband sound absorption of micro-perforated sandwich panels with hierarchical honeycomb core at high sound pressure levelsXindong Zhou, Weitao Zhang, Xiangfei Geng, Fengxian Xindoi:10.1016/j.compstruct.2024.118794 高声压级蜂窝芯微孔夹层板宽带吸声特性研究This paper investigates the effects of high sound pressure level (SPL) on the sound absorption of micro-perforated sandwich panels with hierarchical honeycomb core. Based on the nonlinear sound absorption theory of micro-perforated plates, a theoretical model is established to study the absorption performance of the structure at high SPLs, which is verified by numerical simulations. The results show that under high SPL conditions, the acoustic resistance of the structure is greatly increased and the acoustic reactance of the structure is slightly decreased, resulting in the decrease of the absorption peak values and the increase of the peak frequencies of the structure. The high SPLs can greatly enhance the motion of the air particles in and around the micro-perforation, leading to vortex generation and shedding from the end of the perforation hole. In order to improve the absorption performance of the structure at high SPLs, an optimization algorithm is introduced in the design of the absorber. It is shown that the structure designed with large perforation holes and deep air cavities can achieve good broadband absorption performance at both low and high SPLs. Experimental tests are also carried out to validate the broadband absorption potential of the structure. This work provides guidance for the design and optimization of sound absorbing structures under high sound pressure level conditions.研究了高声压级对分层蜂窝芯微孔夹层板吸声性能的影响。基于微孔板的非线性吸声理论，建立了研究微孔板在高声压下吸声性能的理论模型，并通过数值模拟进行了验证。结果表明：在高声压级条件下，结构的声阻大大增加，结构的声抗略有降低，导致结构的吸收峰值降低，峰值频率增加；高SPLs可以极大地增强微射孔内和周围空气颗粒的运动，导致涡旋的产生和射孔末端的脱落。为了提高结构在高声压下的吸收性能，在吸波器的设计中引入了优化算法。结果表明，采用大孔洞和深空腔设计的结构在低和高SPLs下都能获得良好的宽带吸收性能。实验验证了该结构的宽带吸收电位。该工作对高声压级条件下吸声结构的设计和优化具有指导意义。Fracture from mode I dominated to mixed mode I-II in CFRP repaired steel pipesHuayang Li, Jiayu Wu, Feng-Chen An, Guan Lin, Jian-Fei Chendoi:10.1016/j.compstruct.2024.118798CFRP修复钢管断裂以I型为主，以I- ii型为主External wrapping of carbon fiber-reinforced polymer (CFRP) for the repair of steel pipes with slot-type defects has gained increasing acceptance. Interface debonding between the CFRP and the steel pipe is a common failure mode in this repair system, yet the fracture mechanism remains poorly understood. This paper presents an experimental and theoretical study aiming to elucidate the failure mechanism. A new bonded joint was designed for the experiment, and the debonding process was monitored by the strain distribution of the CFRP using distributed optical fiber sensors (DOFS). Stick-slip fracture behavior was observed in joints bonded with high-strength structural adhesives. Based on the experimental results, theoretical models are developed to describe the debonding process in three stages: elastic stage, rapid crack propagation (RCP) stage, and steady-state crack propagation (SSCP) stage. Using a linear elastic-brittle traction-separation relation, the interface debonding during the elastic and RCP stages is characterized by mode I dominated fracture, analyzed using a cohesive zone model. Mixed mode I-II fracture during the SSCP stage is analyzed using Griffith theory of fracture, with partitioning of the total energy release rate into its mode I and mode II components. The theoretical model aligns well with the experimental results, validating the model’s accuracy.采用碳纤维增强聚合物（CFRP）外包修复槽型缺陷的钢管已得到越来越多的认可。CFRP与钢管之间的界面剥离是该修复体系中常见的破坏模式，但其断裂机制尚不清楚。本文进行了实验和理论研究，旨在阐明其破坏机理。实验设计了一种新型粘结接头，采用分布式光纤传感器（DOFS）对CFRP的应变分布进行监测。观察了高强度结构胶粘剂粘结接头的粘滑断裂行为。基于实验结果，建立了弹性阶段、快速裂纹扩展阶段和稳态裂纹扩展阶段的理论模型。采用线性弹-脆牵引-分离关系，分析了弹性阶段和RCP阶段界面剥离的ⅰ型主导断裂特征，并采用粘聚区模型进行了分析。采用Griffith断裂理论对SSCP阶段的混合I-II型断裂进行分析，将总能量释放率划分为I型和II型分量。理论模型与实验结果吻合较好，验证了模型的准确性。Numerical analysis on tensile behavior and damage mechanism of GLARE laminates with two interacting holes combined with DIC and AE techniquesKejun Hu, Yingxiao Zheng, Yingming Wangdoi:10.1016/j.compstruct.2024.118789结合DIC和声发射技术对具有两个相互作用孔的眩光复合材料的拉伸性能和损伤机理进行了数值分析Stress concentration at the hole edges and inter-hole interference effects are the main factors affecting the mechanical properties of open-hole GLARE laminates. In this paper, a combination of experimental and numerical simulation is used to investigate the effects of the distance between two holes’ edge and fiber orientation on the tensile mechanical properties and failure mechanism of the GLARE laminate with two interacting holes. The strain field at the surface of the GLARE laminate with two interacting holes and the damage progression inside the laminate is monitored in real-time using a combination of digital image correlation and acoustic emission techniques. PCA and K-means++ algorithms are used to evaluate the tensile damage patterns and damage evolution of GLARE laminates. A 3D finite element model with Hashin failure criterion and cohesive zone model is used to predict the tensile behavior of GLARE laminates, and finally, the hole-edge stresses and inter-hole interference behavior were analyzed based on the stress concentration factor. The clustering results show the following damage patterns and corresponding peak frequencies of GLARE laminates during tension: metal /intra-laminar delamination damage [0–50 kHz], matrix cracking [100–175 kHz], fiber/matrix debonding damage [175–220 kHz], inter-laminar delamination damage [220–300 kHz], and fiber fracture [300–400 kHz]. As the distance between the two holes’ edges decreases, the stress interference becomes the main cause of the laminate failure, while the stress concentration becomes the main cause as the distance between the two holes’ edges increases. The stress concentration factor at the edge of the two holes has a higher sensitivity to the direction of fiber orientation compared to the distance between the two interacting holes, which increases significantly with increasing fiber orientation angle.孔边缘应力集中和孔间干涉效应是影响裸眼眩光层压板力学性能的主要因素。本文采用实验与数值模拟相结合的方法，研究了双孔边缘间距和纤维取向对双孔耦合的眩光复合材料拉伸力学性能及失效机理的影响。结合数字图像相关和声发射技术，实时监测了具有两个相互作用孔的眩光层压板表面的应变场和层压板内部的损伤进展。采用PCA和k -means++算法对复合材料的拉伸损伤模式和损伤演化进行了分析。采用基于Hashin破坏准则和内聚区模型的三维有限元模型预测了眩光层合板的拉伸行为，并基于应力集中系数分析了眩光层合板的孔边应力和孔间干涉行为。聚类结果显示，在拉伸过程中，GLARE层叠板的损伤模式和相应的峰值频率为：金属/层内分层损伤[0-50 kHz]、基体开裂[100-175 kHz]、纤维/基体脱粘损伤[175-220 kHz]、层间分层损伤[220-300 kHz]和纤维断裂[300-400 kHz]。随着两孔边缘距离的减小，应力干涉成为层压破坏的主要原因，而随着两孔边缘距离的增大，应力集中成为层压破坏的主要原因。两孔边缘的应力集中系数对光纤取向方向的敏感性高于两孔之间的距离，随着光纤取向角的增加，应力集中系数显著增加。Multi-physics field induced buckling and free vibration of annular perovskite platesZhe Guo, Shaoyu Zhao, Yihe Zhang, Yingyan Zhang, Jie Yangdoi:10.1016/j.compstruct.2024.118791环形钙钛矿板的多物理场诱导屈曲和自由振动Perovskite-based structures and devices have gained tremendous research interest in a wide range of engineering applications yet their mechanical characteristics under combined multi-physics fields remains poorly understood. This paper fills in this gap by investigating the opto-electro-thermo-mechano multi-physics field-induced buckling and free vibration of annular perovskite plates with the effects of photostriction, electrostriction, and thermal expansion properties of hybrid perovskite MAPbI3 crystals being taken into account. Governing equations of the plate are obtained within the framework of the first-order shear deformation plate theory and Lagrange equation method and are solved by employing the Chebyshev-Ritz method. A comprehensive parametric study is conducted to show the effects of light illumination, electric field, temperature change, and mechanical loading on the elastic buckling behavior and free vibration characteristics of the plate. It is found that the combined action of multi-physics fields considerably affects the stability and the fundamental frequency of the perovskite plate, indicating that it is necessary and of great significance to well understand and include the effect of opto-electro-thermo-mechano multi-physics field in structural analysis of perovskite structures for more accurate and reliable engineering design.基于钙钛矿的结构和器件在广泛的工程应用中获得了极大的研究兴趣，但其在多物理场联合作用下的力学特性仍然知之甚少。本文考虑了杂化钙钛矿MAPbI3晶体的光致伸缩、电致伸缩和热膨胀性能的影响，研究了光-电-热-力多物理场诱导的环形钙钛矿板的屈曲和自由振动，填补了这一空白。在一阶剪切变形板理论和拉格朗日方程法的框架下，得到了板的控制方程，并采用切比雪夫-里兹法求解。对光照、电场、温度变化和机械载荷对板的弹性屈曲行为和自由振动特性的影响进行了全面的参数化研究。研究发现，多物理场的共同作用对钙钛矿板的稳定性和基频有较大的影响，说明在钙钛矿结构分析中，充分认识并纳入光电、热和力学多物理场的影响，对提高工程设计的准确性和可靠性具有重要意义。A finite fracture mechanics approach to assess the fatigue life of laminates exhibiting free edge effectsMohammad Burhan, Zahur Ullah, Zafer Kazancı, Giuseppe Catalanottidoi:10.1016/j.compstruct.2024.118797用有限断裂力学方法评估具有自由边缘效应的层合板的疲劳寿命This study presents the application of a 3D Finite Fracture Mechanics (FFM) criterion for predicting fatigue life estimation of laminates exhibiting free edge effects. The proposed 3D FFM fatigue criterion incorporates interface properties such as the critical interlaminar stress and the incremental energy release rate as functions of the number of cycles. Material constants calibration involves computing critical interlaminar stress using effective stress distribution over an average delamination onset width while assuming a quadratic relation between critical incremental energy release rate and nominal remote maximum stress cycle. The 3D FFM fatigue criterion system of equations consists of two inequalities solved for a unique solution by assuming homothetic crack extension and utilising a non-linear constraint optimisation. The proposed methodology predicts that lower angles of ply orientation in angle-ply laminates exhibit greater finite fatigue life for a given remote cyclic load. Predictions of fatigue life estimation align well with the experimental results from the literature.本文提出了三维有限断裂力学（FFM）准则在自由边缘效应层合板疲劳寿命预测中的应用。提出的三维FFM疲劳准则将临界层间应力和增量能量释放率等界面特性作为循环次数的函数。材料常数校准涉及使用平均分层起始宽度上的有效应力分布计算临界层间应力，同时假设临界增量能量释放率与标称远程最大应力循环之间的二次关系。三维FFM疲劳准则方程组由两个不等式组成，通过假设裂纹齐次扩展并利用非线性约束优化来求解唯一解。提出的方法预测，在给定的远程循环载荷下，角层合板的层向角越小，其有限疲劳寿命越长。疲劳寿命估计的预测与文献中的实验结果吻合得很好。Elastic-plastic responses of honeycomb beams under large deformation three-point bendingXinrong Fu, Xiong Zhangdoi:10.1016/j.compstruct.2024.118807大变形三点弯曲下蜂窝梁弹塑性响应The force responses of thin-walled beams under three-point bending can be divided into an elastic–plastic stage and a subsequent buckling stage. An accurate theoretical analysis of the elastic–plastic responses of the beams is the first step to predict their bending responses and help design the beams with better performances. However, the linear small deformation theory is still widely applied in the analysis of beams under three-point bending, leading to significant errors in the elastic–plastic force or bending moment responses of the beams. In this work, the elastic–plastic responses of honeycomb beams are analyzed theoretically with the consideration of the influence of large deformation. A theoretical solution for the bending moment distribution along beams is first derived based on a large deformation bending model. The elastic–plastic responses of the beam are obtained based on the bending moment distribution. Some problems on the large deformation bending theory are then discussed. Finally, the accuracy of the proposed theory is demonstrated. The newly proposed large deformation bending theory predicts the elastic–plastic responses of honeycomb beams with much better accuracy than the small deformation bending theory. The maximum difference in the average bending moment between the theory and simulation drops from 11.2 % to 4.5 %.薄壁梁在三点弯曲作用下的受力响应可分为弹塑性阶段和随后的屈曲阶段。对梁的弹塑性响应进行准确的理论分析是预测其弯曲响应和设计性能更好的梁的第一步。然而，线性小变形理论在三点弯曲梁的分析中仍然广泛应用，导致梁的弹塑性或弯矩响应存在较大误差。考虑大变形的影响，对蜂窝梁的弹塑性响应进行了理论分析。在大变形弯曲模型的基础上，推导了弯矩沿梁分布的理论解。根据弯矩分布得到了梁的弹塑性响应。讨论了大变形弯曲理论中的一些问题。最后，验证了所提理论的准确性。新提出的大变形弯曲理论对蜂窝梁弹塑性响应的预测精度远高于小变形弯曲理论。理论与模拟的最大平均弯矩差由11.2 %降至4.5 %。Composites Part A: Applied Science and ManufacturingImpact response analysis and Physics-Informed damage classification of sandwich composites using electrical resistance-based self-sensingJuhyeong Jang, In Yong Lee, Young-Bin Parkdoi:10.1016/j.compositesa.2024.108665 基于电阻自传感的夹层复合材料冲击响应分析和物理信息损伤分类Sandwich composites face maintenance challenges from low-velocity impacts due to their intricate geometry. We propose a method that uses the self-sensing property of carbon fiber reinforced plastic skins to determine the health of an entire sandwich structure in real time. To reflect the hierarchical nature of impact-induced damage progression and the corresponding increase in signal response, a superposition method was proposed. This method superposes binary classifications to construct a damage index map, addressing the low sensitivity of these specimens and small number of samples. This algorithm achieved an accuracy of 81.36%, which is significantly better than the 74.58–79.69% obtained using the conventional algorithm. Moreover, the color layer yields complementary information on the classification results, instilling confidence in these results. This algorithm has potential applications in hierarchical class relationships. The findings show that self-sensing can be useful in monitoring various complex structures with blind regions.夹层复合材料由于其复杂的几何结构，面临着低速撞击带来的维护挑战。我们提出了一种利用碳纤维增强塑料表皮的自感知特性来实时判断整个三明治结构的健康状况的方法。为了反映碰撞损伤过程的层次性和相应的信号响应增加，提出了一种叠加方法。该方法利用二元分类叠加构造损伤指数图，解决了此类样本灵敏度低、样本数量少的问题。该算法的准确率为81.36%，明显优于传统算法的74.58 ~ 79.69%。此外，颜色层在分类结果上产生补充信息，为这些结果注入信心。该算法在分层类关系中具有潜在的应用前景。研究结果表明，自传感可以用于监测各种具有盲区的复杂结构。Composites Part B: EngineeringDevelopment of de-icing/self-sensing structural composites via controlled Joule heating curingLiberata Guadagno, Luigi Vertuccio, Francesca Aliberti, Roberto Pantani, Marialuigia Raimondo, Michelina Catauro, Raffaele Longodoi:10.1016/j.compositesb.2024.112079可控焦耳加热固化除冰/自感结构复合材料的研制Joule heating curing is among the most promising strategies for obtaining cured structural components. This polymerization methodology consumes less than 1% of the energy required by traditional oven/autoclave processes. In light of the relevant impact on the environmental sustainability of manufacturing processes, several aspects related to this curing methodology have been thoroughly investigated. Structural thermoset resins filled with a percentage of 3% wt./wt. carbon nanotubes (CNTs) were produced by comparing two hardening processes: the classical thermal curing in the oven and the more recent Joule heating curing. The electrical resistance change ratio was monitored during the two curing processes to understand how the hardening reactions and the type of curing process affect the electrically conductive network in the composite. It was found that the alignment of CNTs, also previously detected for traditional curing performed under applied high electric field, mainly occurs in the fluid epoxy mixture's initial curing stage and is maintained thanks to the stiffening caused by the polymerization reactions. CNT alignment was verified through tunneling atomic force microscopy (AFM-TUNA). Furthermore, when the heating occurs in the oven, the resistance (R) of the sample increases sensitively, showing a typical positive temperature coefficient behaviour. An opposite behaviour (negative temperature coefficient) is manifested when the temperature increases via Joule heating by applying an electrical field, obtaining a strong reduction of the sample resistance. Joule heating cured glass fiber reinforced composites manifest the intrinsic coexistence of smart properties (self-heating, de-icing, and self-sensing). The peculiar anisotropic electrical properties conferred by the Joule heating to the glass fiber reinforced composites can be exploited to enhance the efficacy of the self-sensing function in the direction normal to CNTs alignment. The high gauge factor of 39 ± 4 (in the linear region between 0% and 0.33% of strain) was detected. These composites exhibit enhanced smart functions compared to traditionally hardened ones, opening up new possibilities for safety and efficient industrial applications.焦耳加热固化是获得固化结构部件最有前途的策略之一。这种聚合方法消耗的能量不到传统烤箱/高压釜工艺所需能量的1%。鉴于对制造过程的环境可持续性的相关影响，与这种固化方法相关的几个方面已经进行了彻底的研究。结构热固性树脂填充的百分比为3% wt./wt。通过比较两种硬化工艺：经典的烤箱热固化和最新的焦耳加热固化，制备了碳纳米管（CNTs）。通过监测两种固化过程中的电阻变化率，了解硬化反应和固化工艺类型对复合材料导电网络的影响。研究发现，CNTs的排列主要发生在流体环氧混合物的初始固化阶段，并且由于聚合反应引起的硬化而得以维持，而此前在施加高电场的传统固化中也检测到了这种排列。通过隧道原子力显微镜（AFM-TUNA）验证碳纳米管排列。此外，当在烘箱中加热时，样品的电阻(R)敏感地增加，表现出典型的正温度系数行为。当施加电场通过焦耳加热使温度升高时，则表现出相反的行为（负温度系数），从而使样品电阻大幅降低。焦耳加热固化玻璃纤维增强复合材料具有自加热、除冰和自传感等智能特性。焦耳加热赋予玻璃纤维增强复合材料独特的各向异性电学性能，可以提高自传感功能在与碳纳米管垂直方向上的效率。在应变的0% ~ 0.33%的线性范围内，测得高应变系数为39±4。与传统的硬化复合材料相比，这些复合材料具有增强的智能功能，为安全和高效的工业应用开辟了新的可能性。Composites Science and TechnologyRevealing the origin of the thermal conductivity improvement of the silane@polydopamine modified graphene/epoxy nanocomposites: a multiscale studyHaolin Wang, Jihun Lee, Jae Hun Kim, Hyunseong Shindoi:10.1016/j.compscitech.2024.111009 揭示silane@polydopamine改性石墨烯/环氧纳米复合材料导热性改善的起源：一项多尺度研究Recently, silane@polydopamine (silane@PDA) non-covalently functionalized two-dimensional nanofillers have attracted considerable interest in the field of thermal interface materials. This is because silane@PDA effectively enhanced the thermal conductivity (TC) of the nanocomposite without damaging its surface structure. However, from a theoretical standpoint, the origin of the observed TC improvement in silane@PDA modified graphene (silane@PDA-GNP)/epoxy nanocomposites remains unclear. In this study, we propose a multiscale strategy combining molecular dynamics (MD) simulations with a two-step homogenization method to investigate the TC improvement of nanocomposites induced by the silane@PDA non-covalent functional groups. Specifically, the contribution of silane@PDA was quantified based on two aspects: the TC of the effective nanofiller and interfacial thermal transport. The two-step homogenization approach indicates that the silane@PDA functional groups enhance the TC of interphase and out-of-plane TC of silane@PDA-GNP, which are crucial for the enhancement of the nanocomposite TC. The contribution of silane@PDA to the interfacial thermal conductance (ITC) was quantified, and the thermal transport process at the interface was further described by analyzing the interfacial thermal transport mechanisms (interfacial interactions and phonon vibrational power spectra). The silane@PDA functional group excites more phonons at the interphases, which leads to more phonons being involved in the interfacial thermal transport and increased ITC. Additionally, the two-step homogenization approach predicted the effects of different types of silanes and the self-condensation of silanes on the TC of the nanocomposites. The proposed two-step homogenization approach can deepen our understanding of the interfacial thermal transport mechanism, and an efficient and fast computational strategy offers a more practical approach for optimizing thermal interface materials with a high TC.最近，silane@polydopamine （silane@PDA）非共价功能化的二维纳米填料在热界面材料领域引起了相当大的兴趣。这是因为silane@PDA在不破坏纳米复合材料表面结构的情况下，有效地提高了纳米复合材料的导热性（TC）。然而，从理论角度来看，在silane@PDA改性石墨烯(silane@PDA-GNP)/环氧纳米复合材料中观察到的TC改善的起源尚不清楚。在这项研究中，我们提出了一种结合分子动力学（MD）模拟和两步均质化方法的多尺度策略来研究silane@PDA非共价官能团诱导的纳米复合材料的TC改善。具体来说，silane@PDA的贡献是基于两个方面来量化的：有效纳米填料的TC和界面热输运。两步均质方法表明，silane@PDA官能团增强了界面TC和silane@PDA-GNP的面外TC，这是增强纳米复合材料TC的关键。量化了silane@PDA对界面热导的贡献，并通过分析界面热传递机制（界面相互作用和声子振动功率谱）进一步描述了界面的热传递过程。silane@PDA官能团在界面激发更多的声子，导致更多的声子参与界面热输运，增加了ITC。此外，两步均化方法预测了不同类型硅烷和硅烷的自缩聚对纳米复合材料TC的影响。所提出的两步均质化方法可以加深我们对界面热传递机理的理解，并且一种高效、快速的计算策略为高TC热界面材料的优化提供了更实用的方法。Synergistic Multiple Hydrogen Bonds and Reversible Crystallization Effect Enable Ultra-Tough, Self-Healing, and Recyclable Cellulose-Enhanced ElastomerMingming Yu, Mujaheed Halliru Saad, Xiangyu Lin, Fuhao Dong, Xu Fan, Xu Xu, He Liu, Zhanqian Songdoi:10.1016/j.compscitech.2024.111014 协同多氢键和可逆结晶效应使超韧，自愈和可回收的纤维素增强弹性体Incorporating dynamic covalent bonds into polyurethane (PU) elastomers contributes to exceptional self-healing and recyclable properties. However, further applications are seriously limited due to unsatisfying mechanical characteristics. Herein, a self-healing and ultra-robust nanocomposite elastomer is presented here that consists of polyurethane matrix and cellulose nanocrystals through the synergistic gradient hydrogen bonds and strain-induced reversible crystallization effect. Multiple dynamic hydrogen bonds formed between cellulose nanocrystals (CNC) and polyurethane (PHHD) together with the strain-induced reversible crystallized physical network facilitate excellent mechanical properties while maintaining favorable self-healing ability. The introduction of cellulose nanocrystals significantly enhanced the binding energy of the nanocomposite polyurethane elastomer system, exhibiting an increase of 204.32 kJ/mol. Consequently, nanocomposite elastomers display a remarkable tensile strength (up to 50.1 MPa), ultra-high toughness (441.6 MJ/m3), and excellent fracture energy (214.5 kJ/m2) Furthermore, the result found that the introduction of cellulose nanocrystals can reduce the reaction activation energy and obtain nanocomposite elastomers with highly efficient self-healing (93.9 %). The innovative approach is expected to facilitate the development of high-strength, tough, and exceptional self-healing elastomers in academia and industry.将动态共价键纳入聚氨酯（PU）弹性体有助于卓越的自我修复和可回收性能。然而，由于不令人满意的机械特性，进一步的应用受到严重限制。本文通过协同梯度氢键和应变诱导的可逆结晶效应，提出了一种由聚氨酯基体和纤维素纳米晶体组成的自修复超坚固的纳米复合弹性体。纤维素纳米晶体（CNC）和聚氨酯（PHHD）之间形成的多个动态氢键以及应变诱导的可逆结晶物理网络在保持良好的自愈能力的同时，促进了优异的力学性能。纤维素纳米晶体的引入显著提高了纳米复合聚氨酯弹性体体系的结合能，提高了204.32 kJ/mol。结果表明，纳米复合弹性体具有优异的抗拉强度（高达50.1 MPa）、超高韧性（441.6 MJ/m3）和优异的断裂能（214.5 kJ/m2）。此外，纤维素纳米晶体的引入可以降低反应活化能，获得高效自愈的纳米复合弹性体（93.9%）。这种创新的方法有望在学术界和工业界促进高强度、高韧性和卓越的自修复弹性体的发展。来源：复合材料力学仿真Composites FEM