Vari-stiffness characteristics of a 3D SMA hybrid basalt woven composite

2022 ◽  
pp. 115192
Author(s):  
Jun Ke ◽  
Jin Gao ◽  
Zhen-yu Wu ◽  
Zhong Xiang ◽  
Xu-dong Hu
Keyword(s):  
Woven Composite ◽  
Stiffness Characteristics

Particularities of Modelling the Mechanical Properties of Woven Composite Fabrics

2015 ◽  
Vol 809-810 ◽  
pp. 560-565 ◽  
Author(s):  
Andrei Axinte ◽  
Liliana Bejan ◽  
Nicolae Ţăranu ◽  
Victoria Roșca
Keyword(s):  
Mechanical Properties ◽  
Impact Resistance ◽  
Woven Composite ◽  
Fibre Glass ◽  
Discrete Approach ◽  
Stiffness Characteristics ◽  
Woven Reinforcement ◽  
Composite Fabrics ◽  
Longitudinal Modulus ◽  
Transverse Modulus

The mechanical properties of composite fabrics rely on a fabric made by a textile weaving process. In order to use their special ability of being drapeable, instead of just plain weave fabrics, satin or twill reinforcement can be selected. Although some other advantages of the resulting composite, such as good impact resistance or damage tolerance are similar to all woven reinforcement composites, the superior drapeability of satin is a major reason to favour this type of textile reinforcement. This paper is focused on the modelling procedures of stiffness characteristics, specific to satin reinforced laminated composites, using a semi-discrete approach. This method is a compromise between the continuous and pure discrete approaches and is associated with a mesoscopic analysis of the repetitive unit cell (RUC). The elastic properties of the textile reinforced epoxy composite, namely longitudinal modulus and transverse modulus, in case of carbon and fibre glass based 5-harness satin reinforcement, are determined. The differences between the two resulting composite materials and the influence of the various geometric and material parameters involved are studied.

Dynamic Damping and Stiffness Characteristics of the Rolling Tire

2001 ◽  
Vol 29 (4) ◽  
pp. 258-268 ◽  
Author(s):  
G. Jianmin ◽  
R. Gall ◽  
W. Zuomin
Keyword(s):  
Dynamic Behavior ◽  
Variable Parameter ◽  
Low Frequency ◽  
Vertical Load ◽  
Frequency Range ◽  
Inflation Pressure ◽  
Vehicle Simulation ◽  
Dynamic Damping ◽  
Speed Range ◽  
Stiffness Characteristics

Abstract A variable parameter model to study dynamic tire responses is presented. A modified device to measure terrain roughness is used to measure dynamic damping and stiffness characteristics of rolling tires. The device was used to examine the dynamic behavior of a tire in the speed range from 0 to 10 km/h. The inflation pressure during the tests was adjusted to 160, 240, and 320 kPa. The vertical load was 5.2 kN. The results indicate that the damping and stiffness decrease with velocity. Regression formulas for the non-linear experimental damping and stiffness are obtained. These results can be used as input parameters for vehicle simulation to evaluate the vehicle's driving and comfort performance in the medium-low frequency range (0–100 Hz). This way it can be important for tire design and the forecasting of the dynamic behavior of tires.

In-Plane Bending and Shear Deformation of Belt Contributions on Tire Cornering Stiffness Characteristics

2020 ◽  
Author(s):  
Gibin Gil ◽  
Sujin Lee
Keyword(s):  
Mathematical Model ◽  
Shear Deformation ◽  
Beam Theory ◽  
Slip Angle ◽  
Wear Properties ◽  
Angle Change ◽  
Foundation Model ◽  
Plane Bending ◽  
Stiffness Characteristics ◽  
Brush Model

ABSTRACT In radial tires, belt structure plays a role of minimizing the lateral deflection of carcass, which has a significant influence on the cornering and wear properties of a tire. The deflection of carcass affects the magnitude of tread block deformation when the tire is under the slip angle. As a result, it can change the cornering stiffness characteristics of the tire, especially when the vertical load is high. During tire development, a tire design engineer tries to find the optimal belt ply angle that satisfies the various performance requirements simultaneously, but it is not an easy task because the effect of belt angle change is different depending on the size of the tire. There have been many attempts to construct a mathematical model that represents the structural properties of the belt package, including the string-based model and the beam on elastic foundation model. But, in many cases, only the in-plane bending of belt is considered and the shear deformation is not taken into consideration. In this study, the effect of belt angle change on belt stiffness is analyzed using a mathematical model based on the Timoshenko beam theory. This model can account for the in-plane bending and shear deformation of the belt structure at the same time. The results of the analysis show how the contribution of bending and shear is changed depending on a tire design parameter, herein the belt cord angle. The effect of belt ply angle change on cornering stiffness is investigated by means of the brush model including belt flexibility. The prediction by the brush model is compared with the measurement using a Flat-trac machine, and the validity of the model is discussed.

scholarly journals Predicting the overall response of an orthogonal 3D woven composite using simulated and tomography-derived geometry

2020 ◽  
Vol 243 ◽  
pp. 112169 ◽  
Author(s):  
Adam Ewert ◽  
Borys Drach ◽  
Kostiantyn Vasylevskyi ◽  
Igor Tsukrov
Keyword(s):  
Woven Composite ◽  
Overall Response ◽  
Derived Geometry

scholarly journals AE propagation velocity calculation for stiffness estimation in Pier Luigi Nervi’s concrete structures

2021 ◽  
Vol 8 (1) ◽  
pp. 109-118
Author(s):  
Erica Lenticchia ◽  
Amedeo Manuello Bertetto ◽  
Rosario Ceravolo
Keyword(s):  
Propagation Velocity ◽  
Concrete Structures ◽  
P Wave ◽  
Wave Propagation Velocity ◽  
Damage Level ◽  
Stiffness Characteristics ◽  
Vertical Bearing ◽  
The Relationship ◽  
Ae Signals ◽  
Elastic Characteristics

Abstract In the present paper, the acoustic emission (AE) device is used with an innovative approach, based on the calculation of P-wave propagation velocity (vp ), to detect the stiffness characteristics and the diffused damage of in-service old concrete structures. The paper presents the result of a recent testing campaign carried out on the slant pillars composing the vertical bearing structures designed by Pier Luigi Nervi in one of his most iconic buildings: the Hall B of Torino Esposizioni. In order to investigate the properties of these inclined pillars, localizations of artificial sources (hammer impacts), by the triangulation procedure, were performed on three different inclined elements characterized by stiffness discrepancies due to different causes: the casting procedures, executed in different stages, and the enlargement of the hall happened a few years later the beginning of the construction. In the present work, the relationship between the velocity of AE signals and the elastic characteristics (principally elastic modulus, E) is evaluated in order to discriminate the stiffness level of the slanted pillars. The procedure presented made it possible to develop an innovative investigation method able to estimate, by means of AE, the state of conservation and the elastic properties and the damage level of the monitored concrete and reinforced concrete structures.

Experimental and numerical investigations on novel models for mechanical behaviors of the elastic ring in aero-engine

2021 ◽  
pp. 095440622110130
Author(s):  
Zhong Luo ◽  
Lei Li ◽  
Yang Yang ◽  
Xiaojie Hou ◽  
Jiaxi Liu ◽  
...  
Keyword(s):  
3D Model ◽  
Maximum Stress ◽  
Simple Structure ◽  
Experimental Testing ◽  
Axial Direction ◽  
Elastic Ring ◽  
Load Range ◽  
Aero Engine ◽  
Stiffness Characteristics ◽  
First Time

The elastic ring is widely used in elastic support structures of aero-engine because of its simple structure and convenient manufacturing. In this paper, two elastic ring models, 3D and 2D models, are proposed, where the fillets between the bulges and ring are considered. The 2D model is more efficient for the calculation of stiffness characteristics. The 3D model can be used to obtain the maximum stress position in the axial direction. Then the experimental testing is carried out to verify the accuracy and effectiveness of the proposed models. Based on the proposed models, the stiffness nonlinearity and critical load of the elastic ring are found for the first time, which can be used to determine the normal working load range. Moreover, the elastic ring models with and without fillets are developed, and the effect of the fillets on stress is discussed. The results show that the stress is reduced by considering the fillets, which are not considered in the existing literature.

Study on bearing stiffness characteristics with residual stress in carburized layer

2020 ◽  
pp. 095440622096079
Author(s):  
Junshuai Liang ◽  
Ning Li ◽  
Jingyu Zhai ◽  
BaoGang Wen ◽  
Qingkai Han ◽  
...  
Keyword(s):  
Residual Stress ◽  
Contact Stiffness ◽  
Roller Bearing ◽  
High Load ◽  
Axial Stiffness ◽  
Fe Model ◽  
Low Load ◽  
Bearing Stiffness ◽  
Carburized Layer ◽  
Stiffness Characteristics

In this study, a layering method of carburized ring is presented. A finite element (FE) model for analyzing bearing stiffness characteristics is established considering the residual stress in the carburized layer. The residual stress in the carburized layer of a double-row conical roller bearing is tested and the influence of the distribution of residual stress in carburized layer on the bearing stiffness is investigated. Results show that the residual stress in the carburized layer increases the contact stiffness of the bearing by 5% in the low-load zone and 3% in the high-load zone. The radial stiffness of the bearing is increased by 5% in the low-load zone and 3% in the high-load zone. The axial stiffness is increased by 6%, and the angular stiffness increased by 4%. The larger the thickness of the carburized layer, the greater the residual compressive stress in the carburized layer, the deeper the position of the maximum residual stresses in the carburized layer will lead to the greater stiffness of the bearing.

Improvement on Fatigue Performance of 3-D Orthogonal Woven Composite with Nanoclay Modification

2021 ◽  
Vol 22 (1) ◽  
pp. 256-263
Author(s):  
Xiaoping Gao ◽  
Cong Wang ◽  
Wei Wu ◽  
Yonggui Li
Keyword(s):  
Fatigue Performance ◽  
Woven Composite

Boundary and Mixed Friction in the Presence of Dynamic Normal Loads: Part I—System Model

1995 ◽  
Vol 117 (2) ◽  
pp. 255-260 ◽  
Author(s):  
Andreas A. Polycarpou ◽  
Andres Soom
Keyword(s):  
Important Variable ◽  
Friction Model ◽  
System Model ◽  
Dynamic Friction ◽  
Discrete Elements ◽  
Friction Forces ◽  
Contact Compliance ◽  
Stiffness Characteristics ◽  
Nonlinear Normal ◽  
Linearized Model

The instantaneous normal motion between bodies in a sliding contact is an important variable in determining dynamic friction under unsteady sliding conditions. In order to model friction under dynamic conditions, it is therefore necessary to combine a dynamic model of the sliding system with an accurate model of the friction process. In the present work, the nonlinear normal dynamics of a friction test apparatus are described by a linearized model at a particular steady loading and sliding condition in a mixed or boundary-lubricated regime. The geometry is a line contact. The Hertzian bulk contact compliance and film and asperity damping and stiffness characteristics are included as discrete elements. In Part I of the paper, a fifth-order model is developed for the normal dynamics of the system, using both the Eigensystem Realization Algorithm (ERA) and classical experimental modal analysis techniques. In Part II, this system model is combined with a friction model, developed independently, to describe dynamic friction forces under both harmonic and impulsive applied normal loads.

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