现代织物类膜材料力学性能研究进展

Advances in Research on Material Mechanical Properties of Modern Architectural Coated Fabrics

织物膜材因其轻质、高强、耐候性及加工运输便捷等优势,广泛应用于公共建筑、应急救援、航空航天、工业及军事等领域。近年来,为精确分析织物膜结构并推动其在不同领域应用,织物膜材的力学性能成为研究焦点。为此采用CiteSpace对国内外20余年的相关文献进行深入分析,通过可视化知识图谱阐述了织物膜结构研究热点的演化进程,并系统分析了织物膜材测试方法、力学性能及宏–细观本构模型等方面的研究进展。梳理发现国内膜结构的早期研究主要集中在结构找形和静力分析,随着膜结构在我国不同领域的深入运用,相关研究逐渐扩展到材料的本构模型、强度准则、结构风致灾变等方面:1)织物膜材的拉伸性能与其细观结构、基布编织工艺、涂层工艺及纤维类型等多种因素相关,呈现典型的各向异性,其抗拉强度随偏轴角度的增加呈现“U”型和“W”型两种变化特征。2)双轴剪切测试法可使得试件核心区域的剪应力呈均匀分布,目前被广泛应用于膜材剪切性能测试。3)膜材撕裂强度受测试方法的影响显著,现有研究多集中在材料撕裂性能上,初始缺陷对膜结构的静、动力学性能的影响机理需进一步明确。4)目前关于膜结构连接部位的研究多集中在膜片与膜片热合连接试件的面内拉伸性能上,忽略了面外荷载下连接部位易出现的剥离破坏。5)织物膜材本构模型分为细观机理模型与宏观唯象模型,现有的宏观模型基本实现了膜材非线性、非弹性、黏弹性等力学特征的描述,细观模型多注重拉伸刚度预测,缺乏对抗拉强度预测的相关研究。织物膜材的研究目前已取得长足发展,但一些方面仍需进一步研究:1)现阶段织物膜材分类依据单调,未考虑预定用途和特性差异,有必要对其分类依据进一步细化和完善。2)撕裂破坏是膜结构的主要破坏模式,但现行设计规范中并没有得到充分的体现。3)面内拉伸试验难以反映膜材热合区域真实的应力状态、力学性能和失效模式,热合焊接工艺对拼接膜材性能的影响机理有待研究。4)目前关于织物膜材以及连接部位的疲劳性能研究极少,膜材的疲劳损伤机理尚未明确。

Due to the advantages such as lightweight,high strength,weather resistance and convenient processing and transportation,coated fabrics are widely applicated in various domains,including public buildings,emergency rescue,aerospace,industry,and the military.In recent years,to precisely analyze coated fabrics and drive their applications across multiple fields,the mechanical properties have become a central focus.An in-depth analysis of relevant literature spanning over two decades from both domestic and international sources was conducted utilizing CiteSpace.It employs visual knowledge mapping to elucidate the evolution of research hotspots in membrane structure and systematically examines research advancements in testing methods,mechanical properties and macro-micro constitutive models.A review reveals that the early stages were primarily centered around structural form-finding and static analysis.However,with the wide application of membrane structure in different fields in China,the research has been expanded to various fields such as material non-linear constitutive behavior,strength criteria and structural risk assessment.1)The tensile performance of coated fabrics is influenced by various factors,including microstructure,base fabric weaving process,coating technique and fiber type,resulting in distinct anisotropic characteristics.The tensile strength exhibits two distinct variations,resembling a"U"shape and a"W"shape,with increasing off-axis angles.2)Biaxial shear testing methods have been widely adopted to ensure a uniform distribution of shear stress in the core region of specimens and are currently prevalent in assessing shear performance of coated fabrics.3)The tear strength of coated fabrics is significantly influenced by the testing method,with current research predominantly focused on tear performance of coated fabrics.The impact mechanism of initial defects on the static and dynamic performance of membrane structures requires further clarification.4)Presently,research on membrane structure connections primarily emphasizes in-plane tensile performance of bonded connections between membrane panels,overlooking the potential of delamination failures under out-of-plane loads.5)Constitutive models for coated fabrics are categorized into micro-mechanical models and macroscopic phenomenological models.Existing macroscopic models have largely succeeded in describing the nonlinear,non-elastic and viscoelastic mechanical characteristics of coated fabrics,while micro-mechanical models tend to focus more on predicting tensile stiffness,with relatively limited research pertaining to predicting tensile strength.After years of effort,the research on coated fabrics has made substantial progress.However,several issues still require further investigation.1)The current classification of coated fabrics is monotonous and fails to consider differences in intended use and characteristics.2)Membrane structure damage primarily involves tearing,yet design specifications have not been adequately addressed.3)In-plane tensile testing is difficult to accurately reflect the real stress states,mechanical properties and failure modes in the heat-sealed regions of coated fabrics.The impact mechanisms of heat-sealing welding processes on the performance of joint of coated fabrics require further investigation.4)Currently,there is a paucity of research on the fatigue performance of coated fabrics and the connection points,and the fatigue damage mechanisms have yet to be clearly elucidated.