Article
Materials Science, Multidisciplinary
Lin Zhan, Siyu Wang, Shaoxing Qu, Paul Steinmann, Rui Xiao
Summary: In this work, a general approach based on continuum damage mechanics is proposed to model the Mullins effect in soft composites. One-dimensional and three-dimensional damage models are formulated, which successfully describe the stress response in loading-unloading cycles and the anisotropic response of predeformed materials.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2023)
Article
Polymer Science
Miaomiao Qian, Bo Zou, Zhixiao Chen, Weimin Huang, Xiaofeng Wang, Bin Tang, Qingtao Liu, Yanchao Zhu
Summary: The Mullins effect in filled elastomers is significantly impacted by the crosslinking degree of the matrix and the size of the filler. Adjusting the crosslinking degree of the matrix and controlling the particle size of the filler systematically influences the dissipation ratios of different elastomer composites, revealing a characteristic dependence on the composite composition.
Article
Engineering, Mechanical
Balint Fazekas, Tibor J. Goda
Summary: A hyper-visco-pseudo-elastic constitutive equation is introduced in this paper to model the complex behavior of filled rubbers, considering the effects of temperature and residual strains. Model parameters are determined through uniaxial stress relaxation-recovery tests and cyclic uniaxial tensile and simple shear tests at different strain rates, and theoretical results are compared with experimental data for EPDM rubber filled with carbon black.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Materials Science, Composites
Hanyang Gao, Bang Zhang, Fukang Yang, Jiahao Jiang, Guoxin Hu
Summary: This paper investigates the enhancement of mechanical properties of casting polyurethane (CPU) by adding barium ferrites (BFs) as filler. The results show that the strain energy density (SED) and hysteresis energy density (HED) of the nano-BFs-filled polyurethane composite increase significantly, while the hysteresis loss remains almost unchanged. The storage modulus and loss modulus of all nano-BFs-filled polyurethane composites are significantly higher than that of pure polymer, and a small amount of nano-BFs is sufficient to reduce the loss factor, making the material more elastic.
POLYMER COMPOSITES
(2022)
Article
Polymer Science
Ronaldo Ariati, Flaminio Sales, Andrews Souza, Rui A. Lima, Joao Ribeiro
Summary: PDMS is a promising elastomer with various applications, and its properties can be enhanced by mixing with other materials such as fibers or waxes. Few studies have focused on comparing different PDMS composites, showing a need for further research in this area.
Article
Engineering, Manufacturing
C. Ayyanar, Sumit Pramanik
Summary: This study developed a high-performance self-healing composite by preparing short-layers graphene through acid leaching method and using a vascular method to embed Gr/HA in PDMS membranes. The results showed that 2 wt% HA had the highest mechanical properties, while 0.1 wt% Gr composite exhibited the best self-healing performance.
MATERIALS AND MANUFACTURING PROCESSES
(2023)
Article
Materials Science, Multidisciplinary
Sung-Jun Lee, Gang-Min Kim, Chang-Lae Kim
Summary: This study aims to improve the mechanical durability and surface frictional characteristics of polymer/ceramic-based composite materials by adding varying amounts of glass bubbles to polydimethylsiloxane (PDMS). The elastic modulus is proportional to the glass bubble content, while the friction coefficient generally decreases with increasing glass bubble content. A significant reduction in wear rate is achieved when the PDMS:glass bubble ratio is greater than 100:5.
Article
Materials Science, Multidisciplinary
Chengjun Zeng, Liwu Liu, Yunqiang Hu, Wenfeng Bian, Jinsong Leng, Yanju Liu
Summary: In this work, a novel micromechanics-based thermo-viscoelastic constitutive model for shape memory polymer composites (SMPCs) is proposed and applied to four-dimensional (4D) printed SMPCs. The model successfully describes the mechanical behavior, stress-strain curves, stress relaxation, and shape memory behavior of 4D printed SMPCs.
MECHANICS OF MATERIALS
(2022)
Article
Engineering, Mechanical
Shiming Shen, Danming Zhong, Shaoxing Qu, Rui Xiao
Summary: This study develops a unified framework to describe the hyperelastic and damage behaviors of soft materials. The model considers the crosslinked and entanglement parts of the material and incorporates the damage mechanism. The results demonstrate the model's ability to accurately predict the mechanical responses of soft materials.
EXTREME MECHANICS LETTERS
(2022)
Article
Polymer Science
Ning Ma, Guangping Gong, Nannan Li, Bo Li, Xufeng Dong
Summary: DCs composed by dielectric particles and elastomer matrix exhibit electric field dependent deformation, with viscoelasticity dominating their response. The electric field significantly influences the storage modulus of DCs, especially for those with higher particle fraction or aligned distributed particles. The enhanced electrostatic interaction between adjacent particles under electric field plays a key role in this phenomenon.
JOURNAL OF APPLIED POLYMER SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
William Imamura, Erik Oda Usuda, Eder Socrates Najar Lopes, Alexandre Magnus Gomes Carvalho
Summary: Recent research has shown that natural graphite/polydimethylsiloxane rubber composites have promising barocaloric effects, making them suitable for solid-state cooling. By adding natural graphite to the rubber, the composites achieve an increase of up to 500% in thermal diffusivity and thermal conductivity, making them highly potential for solid-state cooling applications.
JOURNAL OF MATERIALS SCIENCE
(2022)
Article
Polymer Science
M. I. Kittur, A. Andriyana, B. C. Ang, S. Y. Ch'ng, E. Verron
Summary: This study focuses on the impact of elastomer network modifications caused by thermo-oxidative aging on the Mullins effect. It investigates the effects of cross-linking and chain scission on the Mullins effect and its recovery through cyclic mechanical tensile loading modes applied to thermo-oxidatively aged specimens. The study characterizes the Mullins effect using two methods to assess the stress-softening caused by thermo-oxidative aging. The observations demonstrate that hysteresis, permanent set, Mullins effect, and its recovery are significantly affected by changes in the elastomer network.
POLYMER DEGRADATION AND STABILITY
(2022)
Article
Materials Science, Multidisciplinary
Rui Xiao, Ning Han, Danming Zhong, Shaoxing Qu
Summary: Compared with traditional single network elastomers, multiple network elastomers (MNEs) can achieve high stiffness and toughness, similar to elastomer composites. The mechanical response of MNEs depends significantly on the prestretching ratio of the filler network, and the damage of the polydisperse network is the underlying mechanism for the Mullins effect. Incorporating the effect of prestretch caused by the matrix in the constitutive model allows for a better description of the stress-strain response of MNEs with varied stretching ratios, surpassing classic damage models based on Langevin statistics.
MECHANICS OF MATERIALS
(2021)
Article
Materials Science, Composites
Vivekendra Singh, Ragnar Larsson, Robin Olsson, Erik Marklund
Summary: This paper addresses the strain-rate effects in a unidirectional non-crimp fabric carbon/epoxy composite and proposes a new model to simulate compression loading at small off-axis angles. The model utilizes computational homogenization to model the matrix and fiber constituents at finite deformation. By improving the homogenized response in transverse shear stress, the model successfully captures the kink-band formation due to localized matrix shearing and fiber rotation, validating the observed increase in compressive strength at high strain rates.
COMPOSITES SCIENCE AND TECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
S. Chockalingam, C. Roth, T. Henzel, T. Cohen
Summary: Measuring local rate dependent mechanical properties with minimally invasive experimental methods is crucial in understanding the behavior of soft and biological materials. Enhancements to the Volume Controlled Cavity Expansion technique have been proposed to characterize the viscoelastic response at low to medium stretch rates. The technique allows for accurate estimation of both quasistatic and dynamic material parameters, addressing possible overestimation of the quasistatic elastic modulus in previous studies.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2021)
Article
Physics, Multidisciplinary
Baihong Chen, Xinning Zhang, Ziliang Wu, Rui Xiao
Summary: Our recent works have shown that hydrogels of poly(methacrylamide-co-methacrylic acid) with moderate water content exhibit similar glass transition behaviors as dry polymers, with high modulus and failure strength. We have applied a viscoplastic model to describe the mechanical behaviors of these gels, including yielding, strain softening, and stress relaxation. This study confirms the shared physical mechanism of glass transition in gels and dry polymers and demonstrates the applicability of classic viscoelastic/viscoplastic models for this new type of tough gels.
Article
Materials Science, Multidisciplinary
Chuanshuai Tian, Lu Dai, Dan Song, Dong Lei, Rui Xiao
Summary: The mechanical response of amorphous glassy polymers is significantly affected by cold rolling. Experiments show a significant increase in hardening response for polymers rolled in the length direction, while much less pronounced strain hardening for polymers rolled in the width direction. Yield strength and strain softening also depend on the rolling conditions.
MECHANICS OF MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Zilu He, Hong Zhang, Rui Xiao, Shaoxing Qu
Summary: This study investigates the mechanical properties of soft composites containing low melting alloys. The results show that increasing the ratio of the alloys enhances the modulus and energy dissipation density of the composites when the deformation temperature is below the melting temperature, while these properties decrease when the alloys are in the fluid state. However, the fracture energy and fatigue threshold are significantly enhanced in the presence of low melting alloys regardless of their states.
ACTA MECHANICA SOLIDA SINICA
(2023)
Article
Materials Science, Multidisciplinary
Lin Zhan, Siyu Wang, Shaoxing Qu, Paul Steinmann, Rui Xiao
Summary: Many classic hyperelastic models cannot accurately predict the stress responses of soft materials in complex loading conditions. We propose a new micro-macro transition approach integrated into a full network framework, which successfully captures the stress responses in multi-axial deformation modes for soft materials. We further develop a two-parameter hyperelastic model that exhibits greatly improved predictive ability for complex loading types compared to other existing models.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2023)
Article
Instruments & Instrumentation
Jie Wang, Zongze Wu, Rui Xiao, Changyu Tang, Yangguang Xu
Summary: We propose a 3D reinforced re-entrant structure (RRS) by adding arrow structures to the classical re-entrant structure (RS). The equivalent elastic modulus and negative Poisson's ratio of RRS can be tuned by various structural parameters. The optimized RRS has an equivalent elastic modulus of 13.67 MPa, which is 12.32 times larger than that of RS with the same negative Poisson's ratio. Therefore, our study provides a potential way for designing engineering materials with desirable performance.
SMART MATERIALS AND STRUCTURES
(2023)
Article
Mechanics
Peng Sun, Tianyu Hu, Lu Dai, Rui Xiao
Summary: A new type of tough double network hydrogels (DN hydrogels) was designed by introducing mechanophores into the first network. When the strands of the first network reach their stretching limit, the mechanophores enable them to survive through force-coupled reactions, resulting in improved mechanical performance compared to conventional DN hydrogels.
INTERNATIONAL JOURNAL OF APPLIED MECHANICS
(2023)
Article
Engineering, Mechanical
Haiming Lu, Yao Tang, Xunuo Cao, Panpan Zhu, Weifeng Zou, Tiefeng Li, Rui Xiao, Haofei Zhou
Summary: This study investigates the change in glass transition temperature (Tg) under different stress states in amorphous materials using molecular dynamics simulations. A theoretical model based on the free volume theory and Eyring model is proposed to quantify the stress dependence of Tg. The potential applications of tuning Tg through external stress and the sensitivity of Tg to hydrostatic and shear stresses are discussed.
EXTREME MECHANICS LETTERS
(2023)
Article
Engineering, Mechanical
Ji Lin, Jin Qian, Yu Xie, Ji Wang, Rui Xiao
Summary: In this study, a micromechanical mean-field shear transformation zone (STZ) model is developed to systematically describe the stress responses of amorphous polymers. The model captures the behaviors of amorphous polymers in various loading conditions and successfully reproduces the Bauschinger effect. The deformation-induced material polarization, in the form of an anisotropic distribution of STZs, is identified as the governing mechanism of the Bauschinger effect.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
Article
Materials Science, Multidisciplinary
Danming Zhong, Yuhai Xiang, Zhicheng Wang, Zhe Chen, Junjie Liu, Zi Liang Wu, Rui Xiao, Shaoxing Qu, Wei Yang
Summary: This study systematically investigates the effect of water content on mechanical behaviors of polyacrylamide (PAAm) hydrogels. It is found that deswelling significantly increases the modulus while swelling decreases it. As the water content decreases, a more pronounced strain-softening phenomenon and a transition from hyperelastic behaviors to viscoelastic behaviors are observed. A micromechanical model is developed to capture these experimental observations and derive the relations between model parameters and water content using scaling laws in polymer physics. The developed model shows remarkable prediction ability and is validated through finite element analysis.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2023)
Article
Materials Science, Multidisciplinary
Lin Zhan, Siyu Wang, Shaoxing Qu, Paul Steinmann, Rui Xiao
Summary: In this work, a general approach based on continuum damage mechanics is proposed to model the Mullins effect in soft composites. One-dimensional and three-dimensional damage models are formulated, which successfully describe the stress response in loading-unloading cycles and the anisotropic response of predeformed materials.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2023)
Article
Materials Science, Multidisciplinary
Shiming Shen, Ning Han, Lu Dai, Rui Xiao
Summary: This study investigates the shape-memory behaviors of multiple network elastomers (MNEs) and finds that they have higher recovery stress, which makes them more suitable for various applications compared to existing shape-memory polymers.
Article
Materials Science, Multidisciplinary
Ji Lin, Honggeng Li, Fengbo Zhu, Qi Ge, Jin Qian, Rui Xiao
Summary: This study comprehensively investigates the mechanical response of an elastomer with physical crosslinkers under fatigue tests. A constitutive model is developed to describe the network configuration and reversible dissociation/association process of polymer chains. The model captures the state transition of the chains, progressive damage in long-term relaxation and fatigue tests, and the rate-dependent stress response and relaxation behaviors of physically crosslinked elastomers and gels.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2023)
Article
Materials Science, Multidisciplinary
Baihong Chen, Changyue Liu, Zengting Xu, Zhijian Wang, Rui Xiao
Summary: In this study, both polydomain and monodomain liquid crystal elastomers (LCEs) were synthesized and their shape change with temperature under a certain stress level was characterized. A thermo-order-mechanical coupling model was developed to predict the shape change of LCEs, showing good consistency with experimental results.
MECHANICS OF MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Liqian Wang, Zhuxuan Wei, Zengting Xu, Qingmin Yu, Zi Liang Wu, Zhijian Wang, Jin Qian, Rui Xiao
Summary: Liquid crystal elastomer (LCE) is a thermally responsive soft material that can be used for fabricating shape changing structures. The anisotropic shape changes of LCEs are different from other stimulus-responsive materials. In this paper, we investigate the bending behavior of bilayer LCEs and propose a strategy to achieve complex deformations by introducing precuts. Our design surpasses other stimulus-responsive materials in terms of shape morphing capabilities, providing possibilities for soft devices and 3D actuators.
ACS APPLIED POLYMER MATERIALS
(2023)
Article
Engineering, Mechanical
Ji Lin, Lu Dai, Jin Qian, Rui Xiao
Summary: This study developed a new constitutive model that incorporates segmental and chain dynamics into the deformation of amorphous polymers and describes the damage evolution and failure behavior. Experimental results compared to theoretical predictions show that the model can capture the observed rate-dependent features.
ACTA MECHANICA SINICA
(2022)
