Quantifying the Mechanical Properties of Materials and the Process of Elastic-Plastic Deformation under External Stress on Material

Abstract

The paper solves the problem of the nonexistence of a new method for calculation of dynamics of stress-deformation states of deformation tool-material systems including the construction of stress-strain diagrams. The presented solution focuses on explaining the mechanical behavior of materials after cutting by abrasive waterjet technology (AWJ), especially from the point of view of generated surface topography. AWJ is a flexible tool accurately responding to the mechanical resistance of the material according to the accurately determined shape and roughness of machined surfaces. From the surface topography, it is possible to resolve the transition from ideally elastic to quasi-elastic and plastic stress-strain states. For detecting the surface structure, an optical profilometer was used. Based on the analysis of experimental measurements and the results of analytical studies, a mathematical-physical model was created and an exact method of acquiring the equivalents of mechanical parameters from the topography of surfaces generated by abrasive waterjet cutting and external stress in general was determined. The results of the new approach to the construction of stress-strain diagrams are presented. The calculated values agreed very well with those obtained by a certified laboratory VÚHŽ.

Application of Laser Profilometry to Evaluation of the Surface of the Workpiece Machined by Abrasive Waterjet Technology

“…Parameters for setting the LPM input values for surface measurement are shown in Table 6. This behavior was in agreement with data observed by Valicek et al [28] and Srivastava et al [29]. The material samples surface roughness values measured were processed, resulting in two graphical dependencies Ra and Rz, for both materials examined.…”

Prediction of Cutting Parameters of HVOF-Sprayed Stellite 6

“…These relate not only to the instantaneous state and changes in the physical-mechanical parameters of the material being machined but also to the condition and changes of the machine tool and the entire technology. The way of dealing with these items is described in detail and is available in granted patents and publications [21][22][23][24][25][26].…”

“…The design model methodology allows them to be tracked along the length of the beam and throughout the load process in connection with the spatio-temporal development of the distribution of the parameters of all the others, in the process of reshaping the involved functions, as shown in more detail below. Complex derivation of Equations (2)-(37) for machining is done in our patented works [24,26] and publications [21][22][23]25].…”

“…The present equation Ra mp = f (R mp , E xpNO ) is sufficient to satisfy this requirement. If we know the integral quantity of roughness, we can derive other main topographical functions according to the previously derived equations of equilibrium [21][22][23][24][25][26] and we can calculate with them further. Further, the Y ret value preferably serves to calculate the tangential forces and the stress for the adhesion control.…”

“…The structure and texture of the surface after machining is sufficiently discretely expressed by equations (Ra, Y ret , a p ) = f (R mp , E xpNO ). For sufficiently discreetly expressed grain size D gr of the coating material was derived [21][22][23][24][25][26] the equation of Equation (35) for different materials. Discrete distribution of particle size distribution by discrete cutting parameters can be determined by D gr = f (R mp , E xpNO ).…”