Inverse Determination of Johnson–Cook Parameters of Additively Produced Anisotropic Maraging Steel

In powder bed-based additive manufacturing (AM), complex geometries can be produced in a layer-wise approach. Results of material science experiments regarding material property identification, e.g., tensile strength, show interdependencies between the test load direction and the layer orientation. This goes hand-in-hand with the measured cutting force, changing with the relative angle between cutting direction and layer orientation in orthogonal cutting tests. However, due to the specific process characteristics, the layer orientation results in anisotropic material properties. Therefore, during machining, the material behaves depending on the buildup direction, which influences the cutting process. To predict this behavior, a simplified inverse approach is developed to determine the buildup direction-dependent parameters of a modified Johnson–Cook model for cutting simulation. To qualify these cutting models, mainly the cutting force and additionally the chip formation examined during orthogonal cuts are used. In the present paper, the influence of the laser-powder-bed-fusion (LPBF) process parameters on subtractive post-processing are shown. A good agreement between verification experiments and simulations is achieved.

An Experimental Study of Nonlinear Behavior of Graphite/Epoxy Laminate under a Three-Point Bending Test

In this work, an attempt has been made to study the experimental of behavior for carbon/epoxy woven laminates under a three-point bending test by varying the support span and the geometrical dimensions of the specimens. Two principles stacking sequences are studied ([45 / 0]2s & [90 / 0]6 ) to observe the effect of the layer orientation in the failure modes. This study has allowed us to confirm the relationship between the bending behavior of the specimens and the span-to-thickness ratio (l/h). Finally, a digital microscope was selected in order to characterize the succession of the failure and the failure modes, mainly the delamination damage.

A Study on Design of Frame Tube Bike Composite for Reducing Stress and Deformation Based on CEN 14766 Standards Test Methodology

In the previous study, frame tube design analysis is developed to provide a significant reduction in stress and deformation. This study aims to analyze the frame tube composite design. The design analysis by using FEM software is used to model frame tubes with shell elements. The layer angle orientation is set as design parameters. Material is carbon fiber composite (epoxy E-glass UD). Dimension thickness is 2 mm. Seat tube angle 74.5oand head tube angle 70.5o. Load is applied in static condition with weight loading on 80 Kg. Based on the simulation results, thesmallest deformation and stress values occur in the model with a layer orientation angle of [45o, 90o, 90o, 45o] with a deformation value of 0.099556 mm and a stress of 10.016 MPa.

Effect of Fibers Orientation on the Fracture of Polymer Concrete Based on Quartz, Polyester and Jute Fabrics

The main objective of this work is to highlight the influence of jute woven layer orientation on fracture parameters (energy release rate and stress intensity factor) of a polymer concrete laminate. The use of plant fibers, jute in this study, as reinforcements outside the polymer concrete, acquires mechanical properties, traction, and flexion, more than appreciable, however, other characteristics must be studied to ensure better integration on the market. The addition of plant fibers with different orientations is not without consequences on the mechanical behavior, in this case, on the resistance to cracking and its propagation. Fibered concretes have a very different behavior compared to non-fiber concretes, especially after the first cracking, where the fibers make their contribution by trying to stop the evolution and the propagation of micro-cracks within the matrix by making the concrete more ductile.

Hardness, friction and wear characteristics of 3D-printed PLA polymer

The mechanical and tribological behaviors of the parts manufactured with 3D printing methods differ with variations in the manufacturing parameters. This paper aims to investigate the effect of the layer thickness and layer orientation parameters on the hardness, friction coefficient and wear properties of PLA samples printed by Fused Deposition Modelling (FDM) method. Samples were printed with three different layer thicknesses in two different build orientations. The hardness of the samples was tested by D-type shore hardness durometer and a pin-on-disc setup was used to measure the friction coefficient and wear rate of the samples. The analysis of the experimental results showed the distinctive effect of the layer orientation and layer thickness which further discussed in the paper.