OPTIMIZATION OF SHEARING PARAMETERS OF CORN STALKS BASED ON DESIRABILITY FUNCTION APPROACH

To determine the parameters of the whole corn stalks shearing, single factor and multi factor tests were carried out by using node and internode critical shearing strength as the evaluation indexes and the moisture content, sampling location and shearing speed as the influencing factors. The results showed that the moisture content, sampling location and shearing speed had significant effects on the critical shearing strength of internodes and nodes (F > F0.05), the order of the influencing factors on the internode and node critical shearing strength were: moisture content >sampling location >shearing speed and sampling location >moisture content >shearing speed. By using Design-Expert and Desirability Function Approach, the optimization problem of three response values, including difference value of critical shearing strength between node and internode at the same segment (DV), the node and internode critical shearing strength, was transformed into a single response value optimization. The corn stalks with a moisture content of 15% had lower shearing strength and higher shearing stability at the shearing speed of 25 mm/min.

KNOWLEDGE-BASED EVALUATION OF PART ORIENTATION DESIRABILITY IN POWDER BED FUSION ADDITIVE MANUFACTURING

In powder bed fusion (PBF) additive manufacturing, the definition of part orientation is one of the most important steps as it affects the quality, the cost and the build time of products. Different works already attempted to propose methodologies for the assessment of optimal build orientation based on criteria such as the minimization of support volume. Elicitation works with industry experts have shown that they use much more varied rules to determine the orientation of parts. For instance, they do not treat the different surfaces of the part the same way (e.g., experts state that “priority surfaces of the part must be oriented close to vertical”). Today, the available tools do not allow integrating these kind of specifications. This paper discusses a knowledge-based methodology for the evaluation of part candidate orientations in PBF. Desirability function approach is used to translate companies’ expertise in the form action rules into mathematical functions that are tested on geometries to provide metrics for assisting the decision-making. A case study is presented to illustrate the use of this desirability function approach on complex part orientation problem.

Optimizing the ultrasonication effect in stir-casting process of aluminum hybrid composite using desirability function approach and artificial neural network

The ultrasonic-assisted stir-casting technique improves the uniform dispersion of nano-reinforcements in aluminum hybrid metal matrix composites. In the present study, the process parameters of the ultrasonic-assisted stir-casting method, such as ultrasonic vibration time, and depth of ultrasonic vibration along with the speed of mechanical stirrer, are optimized on A356 hybrid composite material optimally reinforced with aluminum nitride, multiwalled carbon nanotubes, graphite particles, and aluminum metal powder using the desirability function approach. The process parameters are optimized against the response factors such as porosity, ultimate tensile strength, and wear rate of the composites. The optimum combination of input factors is identified as stirring speed (600 r/min), ultrasonic vibration time (2 min), and depth of ultrasonic vibration (40 mm) among the selected range. The corresponding output response values are found to be porosity (1.4%), ultimate tensile strength (247 MPa), and wear rate (0.0013 mm3/min). The ANOVA results have revealed that depth of ultrasonic vibration showed significant contribution among the input factors. An artificial neural network model is developed and validated for the given set of experimental data.

MODELING AND OPTIMIZATION OF HOLE ACCURACY AND DRILLING TIME IN MAGNESIUM AZ31 PLATE

Owing to the advancement in the field of materials, different range of grades have been developed. The machinability examination of these newer grades must be carried out for future applications. One such newer grade of magnesium with AZ31 is deemed for study during the drilling process. The independent parameters considered are spindle speed (SS), feed rate (FR) and drill bit diameter (DBD). The dependent parameters considered are burr height (BH), burr thickness (BT), drilling time (DT) and surface roughness (SR). Improving hole accuracy is essential for manufacturing superior products, which is discussed in this work. At the same time, the machining time has also to be minimized to increase the production rate. With these objectives, the experimental investigation is made. Further, an analytical model for predicting the responses is developed; later, optimization is carried out to obtain the desired responses through the desirability function approach. The multi-objective optimization suggests the SS of 1100[Formula: see text]rpm, the FR of 0.198[Formula: see text]mm/rev., and the DBD of 6[Formula: see text]mm for reducing the entire dependent is reckoned.