Analysis of thermal management and anti-mechanical abuse of multi-functional battery modules based on magneto-sensitive shear thickening fluid

Electric vehicles(EVs)have garnered significant attention as a vital driver of economic growth and environmental sustainability.Nevertheless,ensuring the safety of high-energy batteries is now a top priority that cannot be overlooked during large-scale applications.This paper proposes an innovative active protection and cooling integrated battery module using smart materials,magneto-sensitive shear thickening fluid(MSTF),which is specifically designed to address safety threats posed by lithium-ion batteries(LIBs)exposed to harsh mechanical and environmental conditions.The theoretical framework introduces a novel approach for harnessing the smoothed-particle hydrodynamics(SPH)methodology that incorporates the intricate interplay of non-Newtonian fluid behavior,capturing the fluid-structure coupling inherent to the MSTF.This approach is further advanced by adopting an enhanced Herschel-Bulkley(H-B)model to encapsulate the intricate rheology of the MSTF under the influence of the magnetorheological effect(MRE)and shear thickening(ST)behavior.Numerical simulation results show that in the case of cooling,the MSTF is an effective cooling medium for rapidly reducing the temperature.In terms of mechanical abuse,the MSTF solidifies through actively applying the magnetic field during mechanical compression and impact within the battery module,resulting in 66%and 61.7%reductions in the maximum stress within the battery jellyroll,and 31.1%and 23%reductions in the reaction force,respectively.This mechanism effectively lowers the risk of short-circuit failure.The groundbreaking concepts unveiled in this paper for active protection battery modules are anticipated to be a valuable technological breakthrough in the areas of EV safety and lightweight/integrated design.

Shear Thickening Fluids Based on Additives with Different Concentrations and Molecular Chain Lengths

Shear thickening fluids （STFs） based on additives with different concentrations and molecular chain lengths were investigated. STF samples were prepared with silica and additive dispersed in polyethylene glycol （PEG） 400, where three types of additives with different molecular chain lengths of PEG4000, PEG6000, and PEG10000 were used. For PEG10000, different concentrations, including 0, 1%, 3%, and 5%, were selected to study the influences of additive concentrations. Rheological properties of the samples were measured with a rheometer. The results show that the shear thickening effect was significantly enhanced with the increase of the concentration and the molecular chain length of additives. The mechanism of enhancement was quantitatively explained with the formation of large particles clusters.

An experimental study on shock wave mitigation capability of polyurea and shear thickening fluid based suspension pads

The present experimental study investigates shock wave mitigation capability of potentially new personal protective equipment(PPE) suspension pads made from polyurea and shear thickening fluid(STF).The shock tube test results show that when placed behind Twaron fabric systems with thickness ranging from 2 mm to 18 mm, the replacement of conventional flexible foam pad with STF and STF-infused foam pads with the same thickness of 20 mm greatly reduces the normalized peak pressure(by about 72% for each pad). However, this benefit is partially offset by a large increase in the normalized impulse(by about78% for the STF pad and 131% for the STF-infused foam pad) which may cause the shock wave mitigation performance of these two pads to become less effective. Interestingly, the use of 4 mm thick polyurea pad can greatly reduce the normalized peak pressure and impulse as well(by about 74% and 49%, respectively). These results reveal that among the potentially new suspension pads tested, the polyurea pad displays the best shock wave mitigation performance. Therefore, polyurea has potential for use as a suspension pad in personal protective equipment requiring shock wave mitigation capability such as fabric ballistic vests, bomb suits and combat helmets.

An experimental study on ballistic impact response of jute reinforced polyethylene glycol and nano silica based shear thickening fluid composite

The present study aims at assessing the ballistic impact behaviour of jute reinforced polyethylene glycol(PEG)and nano silica based shear thickening fluid(STF).Preparation of STF is achieved by dispersing the nano silica particles at different weight percentage loadings of 10%,20%,30%and 40%in PEG and the effect of various weight percentages loading of nano silica particles on ballistic performance of the proposed composites is studied experimentally.Rheological studies of the prepared STF’s showed that at all nanosilica loading shear thickening occurred and also the shear thickening was highest at higher loading of nano silica at lower rate of shear.The study reveals that the ballistic performance of the jute fabric is enhanced with impregnation of STF.The ballistic results indicate that energy absorption of the proposed composites is enhanced with increased loading of nano silica particles and at the same time,the effect of STF was reduced.Specific energy absorption(SEA)of the neat fabric and the proposed composites was made use of for the purpose of comparing the energy absorption capabilities.It is found that the SEA of proposed composites with 10%nano silica loading is lesser than the neat fabric both in case of 3 layers and 6 layers.It was also found that proposed composite with 40%nano silica loading exhibits highest SEA compared to neat fabric and its counterparts with its SEA being 3.21 and 3.76 times highest compared to three and six layers of neat fabrics respectively.

剪切增稠液填充蜂窝夹芯板的低速冲击响应

将气相二氧化硅颗粒与聚乙二醇溶液混合制备的剪切增稠液(shear-thickening fluid,STF)填充到蜂窝芯层中,制成了STF填充蜂窝夹芯板。通过落锤冲击实验,研究了冲击速度(1.0、1.5、2.0 m/s)、蜂窝孔径(2.0、2.5、3.0 mm)和壁厚(0.04、0.06、0.08 mm)对夹芯板力学性能的影响。利用数字图像相关技术测量了结构的应变历史和后面板挠度场的分布情况,探讨了结构的低速冲击响应过程。实验结果表明,在低速冲击下,未填充STF蜂窝夹芯板的变形模式为后面板中心区域凸起变形,周围区域有明显鼓包变形;填充STF蜂窝夹芯板的变形模式为后面板凸起变形且局部凸起区域较大,周围无鼓包产生。STF的剪切增稠效应可以增加参与能量吸收的蜂窝单元,扩大结构的局部变形区域,减小结构的后面板挠度。提高冲击速度、增大蜂窝孔径或者减小壁厚,都更有利于STF的剪切增稠效应。

Mechanical response of encapsulated shear thickening fluid

In this investigation,the hard-to-handle shear thickening fluid(STF)is successfully encapsulated for easy handling and re-processing in the application of promising impact resistant material.Double-walled macroscopic STF capsules are synthesized using a convenient process by instilling the diluted STF droplets into reaction solution.The obtained STF capsules show significant shear thickening response to dynamic impact in comparison to quasistatic compression in terms of 154 times higher absorbed nominal strain energy.This innovative method opens a new window to design and manufacture versatile impact resistant materials and structures.

On Free Boundary Problem for the Non-Newtonian Shear Thickening Fluids

The aim of this paper is to explore the free boundary problem for the NonNewtonian shear thickening fluids.These fluids not only have vacuum,but also have strong nonlinear properties.In this paper,a class of approximate solutions is first constructed,and some uniform estimates are obtained for these approximate solutions.Finally,the existence of free boundary problem solutions is proved by these uniform estimates.

Applications of shear thickening fluids: a review

Shear thickening fluids (STFs) are a type of non-Newtonian fluids. In the equilibrium state, the STFs are in liquid-state. However, they become solid-state under a sudden strike or impact. And when the strike or impact is removed, the STFs can turn back to their equilibrium properties. This paper provides a detailed review on relevant literature related to the applications with shear thickening fluids. It introduced the factors affecting shear-thickening behaviour including volume fraction, particle size, particle shape, carrier fluid viscosity, temperature and some other factors.

On the Study of Magneto-Hydrodynamic Non-Newtonian Fluid Flow throughout Curvilinear Channel with Corrugated Walls

This article aims to numerically investigate the flow pattern for Newtonian and power law non-Newtonian fluid in a semi-half circular channel with corrugated walls under the influence of a magnetic field. The results indicate that, presence of a magnetic field affects the flow field in several aspects, especially in the vortex creation and dissipation. In addition, the analysis is carried out for different Reynolds numbers to ascertain the influence of magnetic field on each flow regime. Eventually, the analysis is carried out for a range of power indices including pseudo plastic (shear-thinning) to dilatants (shear-thickening) fluids. The results show that by increasing the power-index, the vortices begin to form and grow gradually so that in the shear-thickening fluid an extra vortex is formed and created nearby the corrugated part of the channel.

鄂尔多斯盆地东缘深煤层用一体化变黏压裂液研究及应用

结合深煤层大规模压裂开发工艺要求,研发了一套一体化变黏压裂液体系,该压裂液体系由乳液稠化剂、多功能添加剂等组成,可通过调整乳液稠化剂的浓度实时调整为低黏-中黏-高黏滑溜水体系。实验测试表明,该压裂液体系在速溶、增黏、降阻、耐剪切性等方面表现优异:速溶时间20~30 s;在剪切速率为1 s^(-1)→1000 s^(-1)→1 s^(-1)下表观黏度基本不变;流动剪切下降阻率>70%且变化不大。此外,该体系具有较低的表面张力和较好的防膨性能,表现为对煤岩具有较小的岩心伤害率。配合体积改造压裂工艺,在在鄂尔多斯盆地深煤层压裂开发中得到规模化应用,增产效果良好。

剪切增稠流体在Kevlar复合材料中的应用研究进展

高强度、高韧性、低密度的凯夫拉(Kevlar)材料在防护领域广泛应用,但直接使用Kevlar织物制备防护材料会使其过于笨重。因此,人们研究了轻质灵活的Kevlar复合材料,使用剪切增稠流体来增强其性能。本综述总结了使用不同分散相和分散介质的剪切增稠流体浸渍Kevlar复合材料的研究进展,旨在为防护材料的后续研究提供思路。

剪切增稠液增强高发泡率废纸缓冲材料的制备及性能

随着经济的快速增长和人们环保意识的不断增强,植物纤维类环保型发泡缓冲材料逐渐成为研究热点。为改善植物纤维发泡材料发泡率低、缓冲吸能效果差等问题,本研究设计半密闭型发泡模具,成功制备了具有高发泡率和优异吸能性的废纸缓冲材料并对制备工艺进行了优化。结果表明:使用质量分数为0.5%的氢氧化钠溶液预处理废纸浆,不仅可以有效去除废纸中的杂质,而且能在不降低纤维长度的情况下对废纸纤维进行适当改性,有利于提高废纸缓冲材料的发泡率和整体性能。以正交优化试验研究原料配比对废纸缓冲材料性能的影响,并据此确定了最优配方。通过设计全新半密闭型发泡模具,成功制备高发泡率的废纸缓冲材料,其膨胀率相较传统制备方式提高了3~4倍。本研究首次引入剪切增稠液(STF)增强废纸纤维,考察了STF含量对废纸缓冲材料力学性能、发泡倍率和回弹性能的影响,分析了STF对废纸缓冲材料的增强机理。结果表明:STF能够提高单根废纸纤维的强度并增强纤维之间的连结,从而提升缓冲材料吸能性,且随着STF含量的增加,材料的吸能性逐渐增强,发泡率逐渐降低,当STF含量为10%(质量分数,下同)时,STF增强废纸缓冲材料的综合性能达到最优。

剪切增稠液胶囊增强硅橡胶复合材料抗冲击性能的数值模拟研究

冲击会对实战条件下武器的安全性和可靠性带来影响,因此必须使用抗冲击材料来提高武器系统的安全性。随着武器装备的高速发展,传统的聚合物抗冲击材料已逐渐不能满足要求,因此需要开发兼顾高效、轻质、智能、多次防护、多功能的抗冲击防护材料。将剪切增稠液(STF)胶囊分散在硅橡胶中制备了新型抗冲击复合材料,应用LS-DYNA程序ALE算法对落锤冲击STF/硅橡胶复合材料的过程进行了动力学建模,通过数值模拟研究了复合材料的抗冲击性能,并讨论了冲击速度、STF液滴分布结构以及吸能液体对复合材料抗冲击性能的影响。

剪切增稠流体对裂隙地层的封堵特性试验研究

裂隙性地层存在的裂缝型漏失通道通常具有多尺度特性和不确定性,钻井液漏失问题在裂隙性地层进行地质钻探施工中尤为突出。剪切增稠流体(Shear Thickening Fluid,STF)作为一种新型智能材料,具备自感知、自适应和自修复等优良特性,目前已在多领域得到广泛应用。本研究将剪切增稠流体作为一种堵漏材料,通过API堵漏仪单缝管封堵试验,探究了剪切增稠流体在不同分散相浓度(56.9vol%、59.2vol%和61.7vol%)、缝宽(1、2、3、4、5 mm)和压力条件下对裂缝的封堵特性。封堵试验结果表明:漏失量会随着缝宽和时间的增加而增加;纳米SiO_(2)浓度在56.9%~61.7%范围内增加时,会降低漏失速率并减弱缝宽对漏失速率的影响程度;当漏失压力为0 MPa时,剪切增稠流体不产生增稠效应,以液态形式从缝内漏失,压力小幅度增加时会激发其增稠效应,产生团聚状颗粒对缝管进行封堵降低漏失速率;当压力进一步增大超过封堵层承压能力时,剪切增稠流体以板状形态被挤出裂缝。研究剪切增稠流体在堵漏领域的应用,有望为裂隙性地层堵漏提供创新解决方案。

多分散相STF-Kevlar缠绕软壁机匣包容性数值仿真

芳纶织物(Kevlar)缠绕的航空发动机软壁机匣具有质量轻、包容能力强的优点。针对将具有更强抗冲击性能的剪切增稠液(STF)浸渍芳纶织物在航空发动机软壁包容机匣的应用设计,建立了多分散相STF浸渍Kevlar织物缠绕软壁机匣数值模型,开展了不同类型机匣、不同层数织物缠绕机匣及不同叶片转速工况下的机匣包容性能数值仿真研究。结果表明:多分散相STF浸渍Kevlar织物缠绕软壁机匣具有优异的能量吸收能力,其单位质量吸能比纯铝合金机匣的提高了57.4%,比纯Kevlar缠绕软壁机匣的提高了15.2%;织物层数越多,软壁机匣的包容效果越好,3层多分散相STF浸渍Kevlar织物缠绕软壁机匣可使叶片动能降低94.9%;随着转速增大,机匣会由包容转变为非包容,叶片与机匣的接触力逐渐增大,当发生非包容事件时,铝合金内壁的损伤减小,能量吸收降低。

剪切增稠幂律流体中单气泡上升动力学行为的格子Boltzmann方法研究

采用不可压非牛顿气液两相流格子Boltzmann方法研究了剪切增稠流体中气泡上升的动力学行为,重点分析了流变指数n、Eoυos数(Eo)和Galilei数(Ga)对气泡形变、终端速度和剪切速率的影响.数值结果表明:气泡形变程度随Eo的增大而增大,n对气泡形状的影响与Ga相关.另一方面,随着Ga增大,气泡终端速度随n呈非线性单调增大,且n对终端速度的影响随Ga的增大逐渐明显;当Ga固定且值较小时,气泡终端速度在较小Eo下随n的增大先增大后减小,而当Eo较大时终端速度随n的增大呈增大趋势;当Ga固定且较大时,气泡终端速度在Eo较大时较为统一地随n增大而增大.此外,气泡左右两端存在剪切速率较高的区域,该区域尺寸随Eo,Ga的增大而增大,随n的增大先增大后缩小.最后利用正交试验法得到上述三变量对剪切速率和终端速度的影响程度.对于剪切速率,参数影响程度由大到小的顺序依次为n,Ga和Eo;对于终端速度,Ga对其影响最大,n次之,Eo影响程度最小.

剪切增稠流体机理、影响因素及其应用

剪切增稠流体是一种黏度随着剪切速率或外加应力的增加而增加的非牛顿流体,因其独特性质在诸多领域有所应用。介绍了纳米粒子/聚合物悬浮体系和高分子溶液体系的剪切增稠机理和相关的各种影响因素,综述了剪切增稠流体的实际应用情况,对现阶段剪切增稠流体的研究和应用进行了评述。

SiO_(2)/聚乙二醇200/碳纳米管剪切增稠液浸渍芳纶织物及其复合材料防刺性能

为优化高性能织物的防刺性能,采用SiO 2和不同长径比的多壁碳纳米管(MWCNTs)制备多相剪切增稠液(MSTFs),研究MWCNTs的长径比与添加量对剪切增稠液流变性能的影响及MSTFs芳纶复合织物的防刺性能。之后将MSTFs复合织物与碳化硅/聚氨酯(SiC/TPU)涂层织物叠层制备双层防刺复合材料,探究叠层顺序对层合复合材料抗穿刺性能的影响。结果得出:长径比较大的碳纳米管对提高剪切增稠液(STF)的增稠效果更优;随着碳纳米管含量的增加,剪切增稠效果逐渐增强。实验结果表明:MSTFs(0.4%MWCNTs-A)浸渍芳纶织物的最大穿刺载荷较纯STF浸渍芳纶织物提高154.33%;不同叠层结构中以剪切增稠液浸渍织物为面层、SiC/TPU涂层织物为背层的双层复合织物表现出更优的防刺性能。

Experimental study of solid-liquid origami composite structures with improved impact resistance

In this paper,a liquid-solid origami composite design is proposed for the improvement of impact resistance.Employing this design strategy,Kresling origami composite structures with different fillings were designed and fabricated,namely air,water,and shear thickening fluid(STF).Quasi-static compression and drop-weight impact experiments were carried out to compare and reveal the static and dynamic mechanical behavior of these structures.The results from drop-weight impact experiments demonstrated that the solid-liquid Kresling origami composite structures exhibited superior yield strength and reduced peak force when compared to their empty counterparts.Notably,the Kresling origami structures filled with STF exhibited significantly heightened yield strength and reduced peak force.For example,at an impact velocity of 3 m/s,the yield strength of single-layer STF-filled Kresling origami structures increased by 772.7%and the peak force decreased by 68.6%.This liquid-solid origami composite design holds the potential to advance the application of origami structures in critical areas such as aerospace,intelligent protection and other important fields.The demonstrated improvements in impact resistance underscore the practical viability of this approach in enhancing structural performance for a range of applications.

多相剪切增稠液增强柔性层合结构防刺材料的制备及其性能

为提高柔性复合材料的防刺性能,制备多相剪切增稠液(MSTFs),并以流变性能为依据探究剪切增稠液的时效性影响因素;其次,采用纯芳纶织物、MSTFs浸渍芳纶织物与碳化硅/聚氨酯(SiC/TPU)涂层芳纶织物制备不同层合结构的复合材料,进行准静态钉刺和动态刀刺性能研究,探究层合结构对防刺性能的影响。结果表明:MSTF易受到空气湿度的影响,随着储存时间的增加,溶液吸湿后流变性能在短时间内下降幅度较大;在单位面密度下,以浸渍织物在上层、纯芳纶织物在中间、涂层织物在下层的层合结构复合材料表现出最佳的准静态钉刺性能,并且该层合结构6层和15层复合材料也表现出较优的动态防刺性能,研究结果可为防刺服用柔性防刺材料的应用研究提供一定的参考。