Article
Construction & Building Technology
Qiang Fu, Zhenhua Wang, Mengxin Bu, Li Su, Hailei Kou, Ning Li, Ditao Niu
Summary: The uniaxial compressive stress-strain behavior of hybrid basalt-polypropylene fiber-reinforced concrete (HBPRC) with different matrix strengths was investigated in this study. The results showed that basalt fiber (BF) and polypropylene fiber (PF) reduced the damage extent of concrete and changed the failure mode from shear failure to longitudinal splitting failure. Both BF and PF improved the critical strain and peak stress of concrete, with BF having a greater improvement effect than PF. However, excessive addition of hybrid fiber decreased the peak stress of concrete. BF addition increased the concrete's elastic modulus, while PF addition decreased it. The addition of an appropriate amount of hybrid fiber had a positive effect on the concrete's elastic modulus. The toughness of concrete increased with the addition of BF and PF, as well as the increase in matrix strength. When HBPRC was destroyed, BF mainly exhibited tensile failure, while PF mainly exhibited pull-out failure and underwent extrusion and torsion deformation. BF and PF mainly improved the strength and deformation performance of concrete, respectively. A constitutive model considering the effects of both mechanical damage and fiber reinforcement was established for HBPRC.
MATERIALS AND STRUCTURES
(2022)
Article
Mechanics
Simon P. H. Skovsgaard, Simon Heide-Jorgensen
Summary: Delamination is a crucial failure mode in fibre composites, leading to loss of stiffness and ultimately structure failure. Modelling delamination is challenging due to material complexity. A new three-dimensional homogenization approach successfully incorporates delamination into the structural response.
COMPOSITE STRUCTURES
(2021)
Article
Engineering, Multidisciplinary
Stefan Obid, Miroslav Halilovic, Janez Urevc, Bojan Starman
Summary: We propose a novel constitutive model for describing non-linear anisotropic fiber-reinforced materials with different tension and compression responses under a general stress state. The model is based on the original one-dimensional Ramberg-Osgood model, generalized to multiaxial stress and anisotropic material behavior. By using the stress triaxiality invariant as an indicator of stress state type, the model accounts for tension-compression asymmetry under a multiaxial stress state. The model is implemented in ABAQUS/Explicit and verified on two material datasets.
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
(2023)
Article
Engineering, Geological
Zhiwei Gao, Andrea Diambra
Summary: This study proposes a full anisotropic model for fibre-reinforced sand in multiaxial stress space, taking into account the influence of fibre orientation on FRS behavior. The model is based on the deformation of the sand skeleton, the effect of fibre presence on the soil skeleton, and the relative orientation between loading direction and fibre orientation, without requiring direct measurement of individual fibre stress-strain relationships.
Article
Construction & Building Technology
Yonggang Wang, Wanpeng Long
Summary: This paper investigates the mechanical properties of pine needle fibre reinforced concrete under uniaxial compression. The results show that the addition of fibre can improve the mechanical properties of concrete, and using specific treatment methods can achieve optimum results.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Materials Science, Characterization & Testing
Yingyu Wang, Helezi Zhou, Zhengkun Liu, Xiongqi Peng, Huamin Zhou
Summary: This study proposes a general 3D anisotropic visco-hyperelastic constitutive model for unidirectional continuous fiber reinforced shape memory composites. The total energy of the composites is decomposed into isotropic and anisotropic parts, with further decomposition of the matrix part into hyperelastic and visco-hyperelastic parts. A temperature-dependent energy contribution weight factor is introduced to account for the variation of energy contribution during phase transition and shape memory cycle. The proposed model is validated through thermomechanical and shape memory tests on carbon fiber reinforced composites with different fiber inclination angles.
Article
Chemistry, Physical
Andreas Lampropoulos, Demetris Nicolaides, Spyridon Paschalis, Ourania Tsioulou
Summary: The study investigated the tensile behavior of UHPFRC and proposed a constitutive model considering the finite element size to address the size effect on the material. The efficiency and reliability of the proposed method were validated using experimental data.
Article
Engineering, Mechanical
Qiang Fu, Mengxin Bu, Wenrui Xu, Lou Chen, Dan Li, Jiaqi He, Hailei Kou, He Li
Summary: The study found that increasing the volume of hybrid fibers in concrete can enhance the strain rate effect of dynamic compressive strength, but this effect decreases with higher matrix strength. Toughness increases with higher strain rates, volume of hybrid fibers, and matrix strength.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2021)
Article
Engineering, Civil
Qiang Fu, Xu Zhao, Zhaorui Zhang, Gang Peng, Xiaohui Zeng, Ditao Niu
Summary: The dynamic splitting tensile behavior of hybrid basalt-polypropylene fiber-reinforced concrete (HBPRC) was studied, showing an increase in strength and energy dissipation capacity with higher strain rates. The effects of fiber type and content on strain rate sensitivity were consistent with dynamic dissipation energy. Additionally, the addition of basalt and polypropylene fibers improved concrete strength, with the hybrid combination showing the most significant enhancement.
ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING
(2021)
Article
Construction & Building Technology
Heyang Wu, Xiaoshan Lin, Annan Zhou, Y. X. Zhang
Summary: In this study, a constitutive model is developed to simulate the behavior of hybrid fiber reinforced concrete (HFRC) under fire conditions. Empirical equations are proposed to calibrate the relationship between the mechanical properties of HFRC and temperature, considering various influencing factors. The effectiveness and accuracy of the model are validated by comparing simulation results with test data.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Mechanics
Borja Erice, Daniel Thomson
Summary: Unidirectional fibre-reinforced composites are traditionally assumed to be linear elastic before failure, but they exhibit nonlinear responses when loaded. This research explores physically-inspired finite element models to investigate the effects of fibre waviness/misalignment on the elastic modulus and combines it with localization plane plasticity for a complete understanding of the material's mechanical behavior.
COMPOSITE STRUCTURES
(2023)
Article
Mechanics
Federico Accornero, Alessio Rubino, Alberto Carpinteri
Summary: The flexural behavior of steel fiber-reinforced concrete beams is discussed within the framework of Fracture Mechanics. By updating the Bridged Crack Model with a cohesive softening constitutive law of the reinforcement layers, the model is able to describe the global response of the composite including local instability phenomena. The structural response is governed by two dimensionless numbers: the reinforcement brittleness number, N-P, and the pull-out brittleness number, N-w.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2022)
Article
Construction & Building Technology
Mahsa Taheri, Joaquim A. O. Barros, Hamidreza Salehian, Antonio Ventura-Gouveia
Summary: Fibre reinforced shotcrete (FRS) technology, using short fibres instead of steel mesh, has advantages in stabilizing and securing rock and soil systems in underground tunnels. This study investigates the potential of combining strain-softening and strain-hardening fibre reinforced concrete (SSFRC and SHFRC) for tunnel strengthening through numerical simulations. The results show that the proper use of SSFRC and SHFRC can significantly reduce material consumption and improve the strengthening system's efficiency.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2022)
Article
Mechanics
Zhe Xiong, Wei Wei, Feng Liu, Chuying Cui, Lijuan Li, Rui Zou, Yin Zeng
Summary: This study investigated the bond performance of recycled aggregate concrete structures reinforced with fibre-reinforced polymer bars, highlighting the effective corrosion prevention and the key factors influencing bond performance. The findings provide valuable insights for improving the application and design potential of such structures.
COMPOSITE STRUCTURES
(2021)
Article
Engineering, Biomedical
Bruno Rego, Amir H. Khalighi, Joseph H. Gorman, Robert C. Gorman, Michael S. Sacks
Summary: Left ventricular myocardial infarction has significant effects on cardiac function and often leads to ischemic mitral regurgitation, which has deleterious effects and a high mortality rate. Clinical treatments for this condition have limited success due to a lack of understanding of the mitral valve remodeling process. This study developed a computational model to accurately depict the post-MI mitral valve remodeling, suggesting that the valve responds to the infarction through permanent deformations during the initial 8 weeks.
ANNALS OF BIOMEDICAL ENGINEERING
(2023)
Review
Cardiac & Cardiovascular Systems
Divaka Perera, Colin Berry, Stephen P. Hoole, Aish Sinha, Haseeb Rahman, Paul D. Morris, Rajesh K. Kharbanda, Ricardo Petraco, Keith Channon
Summary: Nearly half of patients with angina have non-obstructive coronary artery disease (ANOCA), with two-thirds of these patients having coronary microvascular disease (CMD). Impaired coronary flow reserve (CFR) is associated with myocardial ischemia and adverse cardiovascular outcomes. The CMD workstream aims to improve accuracy of diagnosis and treatment through standardized procedures and various assessment methods.
Article
Engineering, Biomedical
Dan Lior, Charles Puelz, Colin Edwards, Silvana Molossi, Boyce E. Griffith, Ravi K. Birla, Craig G. Rusin
Summary: This paper presents a semi-automatic method for constructing volumetric models of the aortic valve using computed tomography angiography images. The method uses manually selected samples of the aortic segmentation derived from the images to inform the model construction. Valve models for pediatric patients are created and simulation results show that the method produces functional valves that generate pressure and flow waveforms similar to clinical observations.
ANNALS OF BIOMEDICAL ENGINEERING
(2023)
Article
Engineering, Biomedical
Jordan A. Brown, Jae H. Lee, Margaret Anne Smith, David R. Wells, Aaron Barrett, Charles Puelz, John P. Vavalle, Boyce E. Griffith
Summary: Transcatheter aortic valve replacement (TAVR) is a commonly used technique for aortic valve replacement, and computer modeling and simulation (CM&S) can assist in the design and approval process of TAVR devices. This study presents a computational fluid-structure interaction (FSI) model of TAVR using the immersed finite element-difference (IFED) method.
ANNALS OF BIOMEDICAL ENGINEERING
(2023)
Editorial Material
Cardiac & Cardiovascular Systems
Jaclyn Carberry, Daniel Ang, Colin Berry
Article
Cardiac & Cardiovascular Systems
Martha Gulati, Najah Khan, Maria George, Colin Berry, Alaide Chieffo, Paolo G. Camici, Filippo Crea, Juan-Carlos Kaski, Mario Marzilli, C. Noel Bairey Merz
Summary: This study investigated the impact of INOCA (Ischemia with No Obstructive Coronary Arteries) on the quality of life of patients and found that INOCA symptoms were associated with adverse physical, social, and mental health. The study calls for increased patient awareness, physician recognition and diagnosis, and clinical trials to develop evidence-based guidelines for this increasingly recognized cardiovascular disorder.
INTERNATIONAL JOURNAL OF CARDIOLOGY
(2023)
Article
Cardiac & Cardiovascular Systems
Mark A. Hlatky, Sam Wilding, Beth Stuart, Zoe Nicholas, James Shambrook, Zina Eminton, Kim Fox, Derek Connolly, Peter O'Kane, Alex Hobson, Anoop Chauhan, Neal Uren, Gerry P. Mccann, Colin Berry, Justin Carter, Carl Roobottom, Mamas Mamas, Ronak Rajani, Ian Ford, Pamela S. Douglas, Nick Curzen
Summary: The study compares costs between CTCA with selective FFRCT and standard care pathways in the FORECAST trial, and finds no significant difference in US healthcare costs. However, certain factors such as coronary risk factors and planned invasive angiography increase costs.
JOURNAL OF CARDIOVASCULAR COMPUTED TOMOGRAPHY
(2023)
Article
Materials Science, Multidisciplinary
Yangkun Du, Peter Stewart, Nicholas A. Hill, Huabing Yin, Raimondo Penta, Jakub Kory, Xiaoyu Luo, Raymond Ogden
Summary: This paper investigates the application of the classical problem of indentation on an elastic substrate in the field of Atomic Force Microscopy. It highlights that linearly elastic models are insufficient for predicting force-displacement relationships at large indentation depths and suggests a nonlinear indentation model for hyperelastic materials. The authors propose a solution for second-order amplitude deformations and material nonlinearity using second-order elasticity theory, and derive analytical solutions using parabolic or quartic surfaces to mimic a spherical indenter. The results show good agreement with finite element simulations.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2023)
Article
Medicine, General & Internal
Mehrdad A. Mizani, Ashkan Dashtban, Laura Pasea, Alvina G. Lai, Johan Thygesen, Chris Tomlinson, Alex Handy, Jil B. Mamza, Tamsin Morris, Sara Khalid, Francesco Zaccardi, Mary Joan Macleod, Fatemeh Torabi, Dexter Canoy, Ashley Akbari, Colin Berry, Thomas Bolton, John Nolan, Kamlesh Khunti, Spiros Denaxas, Harry Hemingway, Cathie Sudlow, Amitava Banerjee, C. V. D. C. O. V. I. D. U. K. Consortium CVD COVID UK Consortium
Summary: A simple model using national, pre- and post-pandemic electronic health records has been developed to predict excess deaths in the early stages of a pandemic. Despite limited use in emergency preparedness, electronic health records can provide information for pandemic planning and surveillance.
JOURNAL OF THE ROYAL SOCIETY OF MEDICINE
(2023)
Article
Engineering, Biomedical
Debao Guan, Xin Zhuan, Xiaoyu Luo, Hao Gao
Summary: This study develops a model for pathological cardiac growth and remodelling based on constrained mixture theory, which can capture different phenotypes of maladaptive heart growth and remodelling. The model can provide mechanistic insight on anti-fibrotic interventions and be used for heart failure risk assessment and treatment selection.
ACTA BIOMATERIALIA
(2023)
Article
Engineering, Biomedical
Arash Rabbani, Hao Gao, Alan Lazarus, David Dalton, Yuzhang Ge, Kenneth Mangion, Colin Berry, Dirk Husmeier
Summary: An image-based method using cardiac magnetic resonance (CMR) imaging data was developed to estimate the volume of the left ventricular cavity. Deep learning and Gaussian processes were employed to improve the accuracy of estimations compared to manual extraction. A stepwise regression model trained on CMR data from 339 patients and healthy volunteers was able to estimate the volume of the left ventricular cavity during diastole. The method achieved a root mean square error (RMSE) of approximately 8 ml, which is notable considering the automated nature of the estimation.
COMPUTERIZED MEDICAL IMAGING AND GRAPHICS
(2023)
Article
Engineering, Biomedical
Aaron Barrett, Jordan A. Brown, Margaret Anne Smith, Andrew Woodward, John P. Vavalle, Arash Kheradvar, Boyce E. Griffith, Aaron L. Fogelson
Summary: Subclinical leaflet thrombosis (SLT) is a potentially serious complication in patients with bioprosthetic valve after aortic valve replacement, which is associated with increased risk of transient ischemic attacks and strokes. It may progress to clinical leaflet thrombosis and subsequent structural valve deterioration, affecting the durability of the replacement valve. Development of models to simulate leaflet thrombosis and predict patients at risk is crucial, and our approach combines fluid-structure interaction and a simplified thrombosis model for deposition along the moving leaflets. This advancement incorporates adhesion and feedback to fluid-structure interaction, providing valuable insights for modeling thrombosis.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING
(2023)
Article
Computer Science, Interdisciplinary Applications
David R. Wells, Ben Vadala-Roth, Jae H. Lee, Boyce E. Griffith
Summary: The IFED method is a computational approach for modeling fluid-structure interactions using finite element and finite difference techniques. This paper presents numerical and computational analyses of the effects of replacing the projection matrices in the force projection and IFED coupling operators with diagonal approximations. The results show that lumped mass matrices derived from nodal quadrature rules can be used with the IFED method, unlike standard FE methods.
JOURNAL OF COMPUTATIONAL PHYSICS
(2023)
Article
Computer Science, Interdisciplinary Applications
Ebrahim M. Kolahdouz, David R. Wells, Simone Rossi, Kenneth I. Aycock, Brent A. Craven, Boyce E. Griffith
Summary: This paper introduces a sharp-interface approach to simulating fluid-structure interaction involving flexible bodies. The approach combines the immersed Lagrangian-Eulerian (ILE) scheme with the immersed boundary (IB) method for better accuracy and flexibility. The paper presents the formulation, numerical approach, and validation of the algorithm through various benchmarks, including the modeling of a deformable blood clot.
JOURNAL OF COMPUTATIONAL PHYSICS
(2023)
Article
Computer Science, Interdisciplinary Applications
Li Cai, Tong Zhao, Yongheng Wang, Xiaoyu Luo, Hao Gao
Summary: This study used computational modeling to investigate the cardiac dynamics of the mitral valve under normal and pathological conditions. The results showed that the functioning of the mitral valve can greatly impact left ventricular pump function. It was also found that increasing left ventricular filling pressure or myocardial contractility can help compensate for a calcified valve and achieve near-normal pump function.
INTELLIGENT MEDICINE
(2023)
Article
Engineering, Multidisciplinary
David Dalton, Dirk Husmeier, Hao Gao
Summary: Modern computational soft-tissue mechanics models have the potential to provide unique patient-specific diagnostic insights, but their deployment in clinical settings has been limited by the high computational costs of conventional numerical solvers. In this study, we propose an emulation framework for soft-tissue mechanics using a Graph Neural Network (GNN) and physics-informed training, which allows for highly accurate and efficient predictions.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2023)
