An accurate and computationally efficient uniaxial phenomenological model for steel and fiber reinforced elastomeric bearings

2019 ◽  
Vol 211 ◽  
pp. 196-212 ◽  
Author(s):  
Nicolò Vaiana ◽  
Salvatore Sessa ◽  
Francesco Marmo ◽  
Luciano Rosati
Keyword(s):  
Phenomenological Model ◽  
Fiber Reinforced ◽  
Computationally Efficient ◽  
Elastomeric Bearings

scholarly journals Finite Element Analysis for Nonlinear Unbonded Circular Fiber-Reinforced Elastomeric Bearings

2021 ◽  
Vol 5 (7) ◽  
pp. 170
Author(s):  
Pablo Castillo Ruano ◽  
Alfred Strauss
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Carbon Fiber ◽  
Seismic Isolation ◽  
Nonlinear Viscoelasticity ◽  
Fiber Reinforcement ◽  
Special Focus ◽  
Fiber Reinforced ◽  
Element Analysis ◽  
Elastomeric Bearings

In recent years, interest in low-cost seismic isolation systems has increased. The replacement of the steel reinforcement in conventional elastomeric bearings for a carbon fiber reinforcement is a possible solution and has garnered increasing attention. To investigate the response of fiber-reinforced elastomeric bearings (FREBs) under seismic loads, it is fundamental to understand its mechanical behavior under combined vertical and horizontal loads. An experimental investigation of the components presents complexities due to the high loads and displacements tested. The use of a finite element analysis can save time and resources by avoiding partially expensive experimental campaigns and by extending the number of geometries and topologies to be analyzed. In this work, a numerical model for carbon fiber-reinforced bearings is implemented, calibrated, and validated and a set of virtual experiments is designed to investigate the behavior of the bearings under combined compressive and lateral loading. Special focus is paid to detailed modeling of the constituent materials. The elastomeric matrix is modeled using a phenomenological rheological model based on the hyperelastic formulation developed by Yeoh and nonlinear viscoelasticity. The model aims to account for the hysteretic nonlinear hyper-viscoelastic behavior using a rheological formulation that takes into consideration hyperelasticity and nonlinear viscoelasticity and is calibrated using a series of experiments, including uniaxial tension tests, planar tests, and relaxation tests. Special interest is paid to capturing the energy dissipated in the unbonded fiber-reinforced elastomeric bearing in an accurate manner. The agreement between the numerical results and the experimental data is assessed, and the influence of parameters such as shape factor, aspect ratio, vertical pressure, and fiber reinforcement orientation on stress distribution in the bearings as well as in the mechanical properties is discussed.

A Continuum Model for Fiber-Reinforced Soft Robot Actuators

2018 ◽  
Vol 10 (2) ◽  
Author(s):  
Audrey Sedal ◽  
Daniel Bruder ◽  
Joshua Bishop-Moser ◽  
Ram Vasudevan ◽  
Sridhar Kota
Keyword(s):  
Continuum Model ◽  
Applied Pressure ◽  
Experimental Parameter ◽  
Building Blocks ◽  
Axial Rotation ◽  
Parameter Determination ◽  
Fiber Reinforced ◽  
Operational Parameters ◽  
Computationally Efficient ◽  
Design Synthesis

Fiber-reinforced elastomeric enclosures (FREEs) generate sophisticated motions, when pressurized, including axial rotation, extension, and compression, and serve as fundamental building blocks for soft robots in a variety of applications. However, most modeling techniques employed by researchers do not capture the key characteristics of FREEs to enable development of robust design and control schemes. Accurate and computationally efficient models that capture the nonlinearity of fibers and elastomeric components are needed. This paper presents a continuum model that captures the nonlinearities of the fiber and elastomer components as well as nonlinear relationship between applied pressure, deformation, and output forces and torque. One of the key attributes of this model is that it captures the behavior of FREEs in a computationally tractable manner with a minimum burden on experimental parameter determination. Without losing generality of the model, we validate it for a FREE with one fiber family, which is the simplest system exhibiting a combination of elongation and twist when pressurized. Experimental data in multiple kinematic configurations show agreement between our model prediction and the moments that the actuators generate. The model can be used to not only determine operational parameters but also to solve inverse problems, i.e., in design synthesis.

Fiber-Reinforced Elastomeric Bearings for Vibration Isolation

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
James M. Kelly ◽  
Niel C. Van Engelen
Keyword(s):  
Seismic Isolation ◽  
Vibration Isolation ◽  
Fiber Reinforcement ◽  
Compression Modulus ◽  
Additional Parameter ◽  
Fiber Reinforced ◽  
Elastomeric Bearings ◽  
Vertical Stiffness ◽  
Elastomeric Bearing ◽  
Fiber Materials

Fiber-reinforced elastomeric bearings were originally proposed as an alternative to conventional steel-reinforced elastomeric bearings for seismic isolation applications. The flexible fiber reinforcement is a light-weight and potentially cost saving alternative to steel reinforcement which is assumed rigid in the design process. The variety of fiber materials available also serves as an additional parameter for designers to tailor the vertical stiffness of the bearing. In this paper, the analytical solution for the vertical compression modulus of a rectangular elastomeric pad including the effects of bulk compressibility and extensibility of the fiber reinforcement is used to investigate the achievable decrease in vertical frequency. It is shown by an example that the extensibility of the fiber reinforcement can be used to significantly reduce the vertical stiffness in comparison to an equivalent steel-reinforced elastomeric bearing. The resulting decrease in the vertical frequency means that fiber-reinforced elastomeric bearings may have an advantage over steel-reinforced bearings in the vibration isolation of buildings.

Stability of fiber-reinforced elastomeric bearings in an unbonded application

2011 ◽  
Vol 45 (18) ◽  
pp. 1873-1884 ◽  
Author(s):  
Michael G.P. de Raaf ◽  
Michael J. Tait ◽  
Hamid Toopchi-Nezhad
Keyword(s):  
Fiber Reinforced ◽  
Elastomeric Bearings

Investigation of the unbiased probabilistic behavior of the fiber-reinforced concrete's elastic moduli using stochastic micromechanical approach

2020 ◽  
Vol 29 (7) ◽  
pp. 1059-1075
Author(s):  
XZ Liu ◽  
HH Zhu ◽  
JW Ju ◽  
Q Chen ◽  
ZW Jiang ◽  
...  
Keyword(s):  
Orthogonal Polynomial ◽  
Probability Density ◽  
Effective Properties ◽  
Probability Density Functions ◽  
Fiber Reinforced Concrete ◽  
Density Functions ◽  
Fiber Reinforced ◽  
Computationally Efficient ◽  
Linear Transformations ◽  
Micromechanical Approach

The probabilistic behavior of the fiber-reinforced concrete is usually represented by the common probability density functions, which will lead to the biased results. This study aims to develop a stochastic multiphase micromechanical framework with Legendre orthogonal polynomial to investigate the unbiased probabilistic behavior of the fiber-reinforced concrete's moduli. The different phase volume fractions are analytically calculated based on the aggregate grading and the material's effective properties are quantitatively reached by employing the multilevel micromechanical homogenization schemes. The Monte Carlo simulations are adopted to attain the different order moments of fiber-reinforced concrete's effective properties, with which the unbiased probability density functions are reached by using the Legendre orthogonal polynomial approximations and the linear transformations. Numerical examples indicate that the proposed framework is accurate and computationally efficient to characterize the fiber-reinforced concrete's probabilistic behavior.

Sign in / Sign up

Export Citation Format

Share Document