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Investigations of Flow Behavior in Cylinder and Disc Made of Monolithic and Composite Materials
Published in Satya Bir Singh, Prabhat Ranjan, A. K. Haghi, Materials Modeling for Macro to Micro/Nano Scale Systems, 2022
Savita Bansal, S.B. Singh, A.K. Haghi
Solid mechanics is the branch of science used to study the behavior of solid materials and their dynamics. It is the study of the behavior of materials like wood, steel, granite, plastics, alloys, metals, biological materials, engineering material, and so on, when are in motion or/and are under applied internal or external pressure resulting in deformation, thermal changes, chemical interactions, and other electromagnetic properties. Different materials have different physical properties and the usage of the materials for a particular purpose is typically based on their properties. The properties of a solid material include various aspects like strength, toughness, hardness, malleability, brittleness, ductility, creep, etc. One of the very important and common properties that is looked into while choosing a solid material is the material’s strength and its creep.
Stress
Published in Farzad Hejazi, Tan Kar Chun, Simplified Theory, 2021
In engineering, two main types of force are concerned: normal force and shear force. Therefore, normal stress and shear stress are two fundamental types of stress discussed in solid mechanics. Normal stress is developed by a normal force acting perpendicularly to a plane (Fig. 2.2) while shear stress is developed by a shear force acting parallelly to a plane (Fig. 2.3). Normalstress,σ=FA where
Mechanical System Failure
Published in Seong-woo Woo, Design of Mechanical Systems Based on Statistics, 2021
The main difficulty in designing against fracture in high-strength materials is that the pre-existence of cracks can modify the local stresses to such an extent that the elastic stress analyses done so carefully by the designers are inadequate. When a crack extends to a definite crucial length, it can propagate catastrophically through the structure, even though the gross stress is much less than would usually cause yield or failure in a tensile specimen. The term ‘fracture mechanics’ refers to an essential specialization in solid mechanics in which the existence of a crack is presumed, and we wish to search out quantitative relationships between the crack length, the material’s intrinsic resistance to crack growth, and the stress at which the crack propagates at high speed to give rise to a structural failure.
Detection and evaluation of thermal aging brittleness of heat-resistant steel using magneto-acoustic compound techniques
Published in Nondestructive Testing and Evaluation, 2023
Yanhong Guo, Zenghua Liu, Xin Zhao, Cunfu He, Bin Wu
In particular, the size of the grid in the simulation model should be at least greater than 8 wavelengths, in accordance with the general simulation parameters. The grid size can be made smaller to shorten calculation time by lowering the frequency and wavelength of the excitation signal. As a result, we employ an excitation signal with a 0.5 MHz central frequency. As shown in Figure 11, the half-cycle sinusoidal signal modulated by Hanning window was used to further prevent the wave packet aliasing of the received time-domain signal and lessen the difficulties of signal processing and analysis in the subsequent stage, and the expression of the signal is J0 = 20sin (2πft). In the model, the Lorentz force was set to the body force in the solid mechanics field, and the magnetostriction module was coupled to the solid mechanic field.
Influence of phase transformation on stress wave propagation in thin-walled tubes
Published in Waves in Random and Complex Media, 2023
When solid materials are subjected to strong impact loads—such as an explosion, thermal shock, or high-velocity impact—they may yield or even undergo phase transformation. Phase transformation can greatly affect the mechanical response of materials and structures because the transformed material can be regarded as another material. This is a common concern in the fields of materials science, solid mechanics, and industrial manufacturing [1]. Shape memory alloys (SMAs) are typical functional materials that have many excellent properties, such as the pseudo-elastic effect and shape memory effect. Owing to their unique thermal and mechanical properties, SMAs have received extensive engineering attention, especially in applications involving high precision and military purposes, including in the aerospace, automotive, biomedical, and oil-exploration industries [2]. With recent increases in their application in explosive and impact environments, the dynamic response and mechanical behavior of SMAs need to be further explored [3].
Design and printing of embedded conductive patterns in liquid crystal elastomer for programmable electrothermal actuation
Published in Virtual and Physical Prototyping, 2022
Ziyao Huo, Jiankang He, Huayan Pu, Jun Luo, Dichen Li
For FEA, applied voltage was used as the loading condition and heat convection with air was set as boundary condition (Figure S3). The temperature distribution (Figure 1d(i)) was firstly calculated in electrical heating module and heat transfer module. Due to the difference in thermal expansion coefficient between LCE-CB and PI, thermal stress would be generated as the heating temperature increased, which led to the deformation of the electrothermal actuator (Figure 1d(ii)). The resultant temperature distribution data was invoked in the solid mechanics module to calculate the thermal stress and strain for deformation prediction. The thermal strain equation of LCE-CB, defined as the relationship between the temperature and the shrinking strain is important for finite element-based deformation prediction, which was experimentally obtained according to the previous publication (Cui et al. 2018). Briefly, the LCE-CB strip was gradually heated from 23°C to 120°C with an increasing temperature interval of 10°C (the first interval is 7°C). At the end of each heating interval, the shrinking strain of the LCE-CB strip was measured. The thermal strain equation at specific temperature interval was linearly fitted from the starting point and the end point (Figure S4), which was used as the input variable in the FEA model.