Papers by Keyword: Strain Energy

Abstract: A Group of three specimens from 1312 steel were subjected to a range of elevated temperatures (700, 800, 900) Celsius to demonstrate the hazard of fire on steel columns mechanical proprieties. The results show a dangerous increase in creep strain buckling after 60 minutes from the beginning of the test and after 67 minutes failed to occur. Mechanical tests for normal and elevated temperatures were made to compare the fire hazards, the results depict reduction by 29%, 46%, 55% for young modulus of elasticity for elevated steel specimens (700, 800, 900) °C. for yield strength the value decreased by (128.4, 169.6, 189) Mpa for specimens (700, 800, 900) °C respectively. The ultimate stress reduction by (64, 78, 83) % from the normal value. whenever higher temperatures go up the lower the ultimate strain falls dawn by (50, 60, 66) % to the original ultimate strain value 0.5. the 0.2 strain % is decreased from 0.0029 to 0.0027 for 700 °C and increased to 0.011, 0.015 for (800, 900) °C respectively.

Abstract: The paper presents the results of numerical experimental studies of cutting titanium blanks using mathematical modeling programs, which make it possible to completely repeat technological processes in a computer (digital twin). The LS-DYNA product was used as a program to simulate the process of stock removal from titanium blank. It has been established that the use of this method adequately describes the cutting processes, including with the introduction of the energy of an ultrasonic field into the processing zone, can significantly reduce the duration of experimental research and evaluate the influence of the elements of the cutting mode and design parameters of the tool on the thermal power aspects of the formation of new surfaces of machine parts.

Abstract: As a type of nanostructured material with nanosized porosity and ultrahigh specific surface area, nanoporous metals attract much attention in both industrial and theoretical fields. Through molecular dynamics simulations, the strain energy of nanoporous copper is investigated with special consideration on the effect of temperature and strain rate. First, with the variation of temperature and strain rate, the change of both stress and strain energy is plotted. Dislocation movement and structural response of nanoporous copper are explored in different stages of strain. Secondly, yield points under different conditions are analyzed to demonstrate the super plasticity of nanoporous copper. It is interesting that critical points appears. Based on above mentioned investigation, it is expected to provide a simple description on mechanical property and performance of nanoporous metals.

Abstract: In this present work, TiN films with various thicknesses (from 0.3 μm to 2 μm) were deposited by DC reactive magnetron sputtering on Ti6Al4V substrates. The evolution of texture and microstructure were studied by X-ray diffraction and Scanning Electron Microscopy, respectively. The XRD characterization indicates that the preferred texture of TiN films is changed from (111) to (100) with increasing the film thickness. The microstructure characterization shows that their microstructure transform from continuous into columnar with increasing the TiN film thickness. It is considered these results are arised from the change of overall energy including surface energy and strain energy with the film thickness. The hardness of TiN film increases with increasing the film thickness.

Abstract: Mechanical alloying (MA) is a potential processing method for various equilibrium and non-equilibrium alloy phases such as supersaturated solid solution, metastable crystalline, amorphous, quasi-crystalline phases, nanostructures. Compared to conventional high temperature material processing such as melting and casting, improvement of solid solubility limit results from mechanical alloying at room temperature. The solid solubility increases with increase in milling time due to enhanced stress assisted atomic diffusion during particle refinement and reaches a saturation level at higher milling time. The extension of solid solubility is attributed to thermodynamic, dynamic or kinetic factors such as high dislocation density due to severe plastic deformation during particle refinement and enhanced diffusivity during MA. The review aims to discuss the insight of MA than other non-equilibrium processing in terms of achieving higher solubility, reasoning and mechanism of solubility improvement during MA of different alloy systems.

Abstract: This paper indicates the difference between the strengthened reinforced high performance concrete beams and the normal reinforced high performance concrete beams. This paper shows the cyclic behaviour of the two types of beams. Experimental investigations were carried out on reinforced High Performance Concrete (HPC) beams of size 150 mm × 250 mm × 3000 mm under both static loading and cyclic loading separately under four point bending. It was observed that the trend in behaviour of the load-deflection curve of the beams was showing the same trend of normal reinforced concrete beams under static loading. In static loading the strain energy absorbed by the beams were observed to be the same as calculated with the area under the load-deflection curve. Other beam was tested under cyclic load separately. The load applied was 35% of static ultimate load which was uniform throughout the fatigue testing of the beams. It was observed that the deflections were increased with the number of cycles. Some of the beams were strengthened by different types and thickness of the GFRP sheets. It was also observed that the strengthened beams withstood more number of cycles than normal HPC beams. The paper presents in detail the experimental investigations conducted on beams and pertinent conclusions drawn therefrom.

Abstract: The concentrated elastic-plastic contact was studied on a thin disc loaded by axial pressure in the central part. Components of energies and stresses were determined via a simple model and discussed.

Abstract: Automobile industries have shown more interest for the replacement of conventional steel leaf spring with that of the composite leaf spring due to its high strength to weight ratio. The objective of the work is to carry out computer aided design and analysis of composite (Glass fiber reinforced plastic) leaf spring and conventional steel leaf spring by considering certain parameters like stress, deflection and strain energy with similar design considerations and loading conditions. The material of the conventional leaf spring is 65Si7 and composite leaf spring is S2-Glass\Epoxy. The CAD model of the leaf spring is modeled in Pro-E and the numerical analysis is carried out using finite element analysis, ANSYS 14. Stress, deflection and strain energy results of both steel and composite leaf spring are obtained and compared. The result shows that the composite leaf spring has maximum strain energy than conventional steel leaf spring and weight of the composite leaf spring is nearly reduced up to 85% compared with steel material.

Abstract: The strain energy of dam body and its sensitivity to the deformation modulus of foundation are taken as objective functions, feasibility robust constraint of stress is taken into account with the consideration of uncertainty of foundation deformation modulus, and a robust optimization model for shape design of arch dams is established based on strain energy. A formula of sensitivity of dam strain energy to deformation modulus of foundation is derived and a relevant algorithm is proposed. The optimization of a planned arch dam indicates that, the dam strain energy and its sensitivity to foundation deformation modulus of optimal design are reduced 2.29% and 15.51%, respectively, of that of initial design, and the validity of the proposed model is demonstrated.

Abstract: In this paper a volume criterion based on a simple scalar quantity, the mean value of the strain energy (SED), has been used to assess the static strength of notched components made of Polymethylmethacrylate (PMMA). The local-strain-energy based approach has been applied to a well-documented set of experimental data recently reported in the literature. Data refer to blunt U-notched cylindrical specimens of commercial PMMA subjected to static loads and characterised by a large variability of notch tip radius (from 0.67 mm to 2.20 mm). Critical loads obtained experimentally have been compared with the theoretical ones, estimated by keeping constant the mean value of the strain energy in a well-defined small size volume. In addition, some new tests dealing with V-notched specimens with end holes have been carried out to investigate the effect of the notch opening angle.