Papers by Keyword: Finite Element Analysis (FEA)

Abstract: The combination of additive manufacturing technology and cartilage tissue scaffold construction provides a new way for clinical treatment of cartilage injury. The high priority of the cartilage scaffold is closely related to the excellent biomechanical properties, fatigue life and medical performance. In this paper, three kinds of cartilage scaffolds are designed, and three-dimensional parametric geometric and numerical simulation models are established. Based on the simulation analysis and comparison of the three kinds of scaffolds, a scaffold model is finally determined. The porosity reaches 87.38%, the equivalent elastic modulus is 9.64Gpa, and it has permanent fatigue life in service environment. It concluded that the designed Ti6Al4V titanium alloy scaffold is suitable for cartilage transplantation.

Abstract: Polycrystalline diamond (PCD), is a tool material and widely used in nonferrous metal processing due to its excellent properties, such as high hardness, high wear resistance, high thermal conductivity and low friction coefficient. Considering the friction between the cutter and the workpiece, the heat generated by the elastic-plastic deformation and the heat transfer between the cutter and the workpiece. The finite element analysis software ABAQUS was used to study the effect of different processing parameters on the temperature field distribution and cutting force of the cutter, in the case of welded PCD double-edge end milling copper. The temperature distribution of cutting tools and the changing trend of cutting force with milling parameters was obtained. These technological parameters include the milling rotation speed n, the axial milling depth a_p, and the feed rate f. The simulation results show that the tool temperature increases with the increase of milling depth, feed per revolution and rotation speed. However, the tool temperature has little effect on the tool life. Under the condition of satisfying the work-piece surface quality and machining efficiency, low speed, small milling depth and small feed should be selected as far as possible. Milling depth has a great influence on cutting force. When milling speed is about 2400 r/min, the axial milling depth is 0.3 mm, and the feed is 0.2 mm/r, which can obtain small milling force and lower tool temperature, and further extend the life of PCD tool.

Abstract: Thanks to their high damage detection sensitivity and low requested power consumption, guided-waves (Lamb waves) have been increasingly used in the last years to monitor the structural integrity in primary and secondary composite structures. The monitoring of the structural health through the propagation of Lamb waves in composite structures is notoriously complex and, for this reason, the development of a prediction model can be a helpful tool for the improvement of Structural Health Monitoring (SHM) systems. Finite Element Method (FE) appears to be the best candidate for such type of simulation. However, since Lamb waves propagation depends strictly on the local material properties of the medium they propagate through, their numerical characterization is a thorny phase. Real composite components are usually affected by the presence of a large number of voids and defects, which cannot be reproduced in numerical models; this leads to a variability of the mechanical properties of materials, with particular reference to elastic moduli and density. These aspects get really ambitious the development of a well-established FE model. In this paper, a design of experiment (DOE) has been carried out to numerically investigate on the effects of the material properties variability on guided-waves time of flight.

Abstract: The paper presents a series of aspects regarding the design, manufacturing (through Rapid Prototyping) and FEA analysis of an intervertebral disk made from UHMWPE. In the first part are presented the most used model existing on the market. The CAD model and Finite Element Analysis (FEA) of the intervertebral disc (IVD) were made using the SolidWorks program. As a material, UHMWPE has been preferred due to good mechanical and biocompatibility characteristics.

Abstract: Laminated composite plates are widely used in the aerospace field, the prediction of their residual life is a interesting challenge for research communities. Their structural behaviour could be affected by several rupture mechanisms due to exercise loading conditions. One of the most critical is the low velocities impacts with different impact energies. This paper deals with an experimental test program performed in order to validate a numerical model developed by using finite element method. All experimental tests were carried out under international standard ASTM D7136 while all numerical tests were carried out by use of a worldwide numerical code Abaqus®. Inter-laminar and intra-laminar rupture mechanisms were taken into account and special-purpose elements were used. Rupture criteria were implemented in the numerical models thanks to their functional ease; results of numerical-experimental comparison were presented and discussed.

Abstract: As it stands now, rubber has been the main material used in the making of pneumatic vehicle tyres. Speed of the vehicle depends on many factors like steering geometry, inflation pressure, vehicle load, road temperature and environmental conditions. The main aim of this research is to develop a finite element approach and computationally evaluate the performance of a steady-state rolling tyre by changing the tyre tread patterns. The tyre normally composed of rubber and body-ply was investigated with regards to the effect of the inflation pressure. Tyre modeling using six different types of patterns was completed by using Creo parametric 3D modeling software and then the tyre was discretized into small elements through ANSYS R16.2. The rim area of the tyre was fixed and pressure was applied to the inside surface of the rim. Finite element analysis was completed by using ANSYS R16.2 and equivalent stress, contact stress and contact pressure were found out to identify the best tyre pattern. From the final results it was observed that, Pattern-I had good agreement of results as compared to other type of patterns which showed medium frictional stress and contact pressure.

Abstract: The radial spokes of non-pneumatic tire have been developed to absorb impacts. In order to obtain its property for the further developments, it had to cut into the curve beam specimens. The 3-point bending was selected to test referring to ASTM D790. Subsequently, the finite element method was employed to simulate the 3-point bending test of specimens. The inverse method was used to determine the modulus of elasticity for specimen material. The gradient based on optimization scheme was used to optimize the modulus of elasticity by the input and output condition which was the vertical deflection and force, respectively. The optimized process was terminated at the desirable force tolerance of 0.00071 N. The elastic modulus of spoke was implemented in the finite element model of the 3-point bending test. There was found that the simulation result of vertical displacement obtained an average error of 4.87% by comparing with physical experiment.

Abstract: These are developed to the Eco-composite structure for using of the rural building materials. The chemical and physical properties were carried associated with Ratchaburi lateritic red soil and cellulose fibers for product development. Also mechanical testing, thermal conductivity, leachability, environmental toxic and Finite element analysis (FEA) were conducted for product evaluation.

Abstract: Finite elements analysis has been performed to compute a J-integral values in a notched pressure vessel. A semi-elliptical notch was introduced in a wall of cylindrical pressure vessel with aspect ratio of notch depth to wall thickness a/w = 1/6 to 5/6, where the wall thickness was 3 mm. Two cases were examined – inner and outer notch. Numerical examinations were revealed that outer notch has much higher values of J-integral (3-4 times), all other being the same, (i.e. inner pressure and dimensions of the notch). That was explained in terms of triaxality stress state in front of notch. Namely, it was shown that inner notch has positive triaxiality stress ratio and vice-versa, outer notch revealed highly negative hydrostatic stress component ahead the notch.

Abstract: A Finite Element (FE) model is used to simulate the experimental behaviour of high strength bolts in asymmetric friction connections (AFC). Two M16 connections tested previously are modelled using ABAQUS and are subjected to cyclic lateral displacements. The numerical results were similar to that from previous experimental studies. It was also shown that hysteresis loop strength and stability reduced for longer bolt grip lengths. Other information, which cannot be easily monitored in experimental tests, such as the bearing stress distribution between plates, component equivalent plastic strain, and bolt tension force, were obtained at different sliding distances. It was shown that bolt and plate plastic deformation tended to occur in bolts with a long grip length to bolt diameter ratio.