Function-Based Computer Aided Conceptual Design Support Tool

Conceptual design is considered as the most critical and important phase of design process. It is the stage where product’s fundamental features are determined, large proportion of the lifecycle cost of the product is committed, and other major decisions are made, which have significant impact on the downstream design and related manufacturing processes. It is a knowledge intensive process where diverse knowledge and several years of experience are put together to design quality and cost effective products. Unfortunately, computer support systems for this phase are lagging behind compared to the currently available commercial computer aided design (CAD) tools for the later stage of design to reduce the designers workload and product development time. The overall goal of this research is to provide designers with computational tool that support conceptual design process. To achieve this goal a methodology that integrates systematic design approach with knowledge-based system is proposed in this thesis. Accordingly, a framework of computer based computational tool known as conceptual design support tool (CDST) is developed using the proposed methodology. The tool assists designers in performing functional modeling by providing standard vocabularies of functions in the form of function library, generate concepts stored in the database from previous designs, display the generated concepts on the morphology chart, combine the concepts and evaluate the concepts variants. Concepts from subsea processing equipment design have been collected and saved in the database. The tool also accepts new concepts from the designer through its knowledge acquisition system to be saved in the database for future use. In doing so, it is possible to integrate human creativity with data handling capabilities of computers to perform conceptual design more efficiently than solely manual design. The tool can also be used as a knowledge management system to preserve expert’s knowledge and train novice designers. The applicability of the proposed methodology and developed tool is illustrated and validated by using a case study and validation test conducted by independent evaluators

Function-Based Computer Aided Conceptual Design Support Tool

Conceptual design is considered as the most critical and important phase of design process. It is the stage where product’s fundamental features are determined, large proportion of the lifecycle cost of the product is committed, and other major decisions are made, which have significant impact on the downstream design and related manufacturing processes. It is a knowledge intensive process where diverse knowledge and several years of experience are put together to design quality and cost effective products. Unfortunately, computer support systems for this phase are lagging behind compared to the currently available commercial computer aided design (CAD) tools for the later stage of design to reduce the designers workload and product development time. The overall goal of this research is to provide designers with computational tool that support conceptual design process. To achieve this goal a methodology that integrates systematic design approach with knowledge-based system is proposed in this thesis. Accordingly, a framework of computer based computational tool known as conceptual design support tool (CDST) is developed using the proposed methodology. The tool assists designers in performing functional modeling by providing standard vocabularies of functions in the form of function library, generate concepts stored in the database from previous designs, display the generated concepts on the morphology chart, combine the concepts and evaluate the concepts variants. Concepts from subsea processing equipment design have been collected and saved in the database. The tool also accepts new concepts from the designer through its knowledge acquisition system to be saved in the database for future use. In doing so, it is possible to integrate human creativity with data handling capabilities of computers to perform conceptual design more efficiently than solely manual design. The tool can also be used as a knowledge management system to preserve expert’s knowledge and train novice designers. The applicability of the proposed methodology and developed tool is illustrated and validated by using a case study and validation test conducted by independent evaluators

Improving Lifetime of Domestic Compressor Subjected To Repetitive Internal Stresses

To enhance the lifetime of a mechanical system such as compressor, parametric accelerated life testing (ALT) as a systematic reliability method is proposed. It consists of (1) a parametric ALT plan formed on BX lifetime, (2) load examination for ALT, (3) a customized parametric ALTs with design alternatives, and (4) assessment of the compressor design to secure the objective BX lifetime is fulfilled. As an experiment instance, newly designed reciprocating compressors for French-door refrigerators returned from the marketplace were investigated. The refrigerators had been making disagreeable noise and vibrations, creating the consumer to ask for replacing their refrigerators. As the vibration level of the problematic refrigerators was recorded in an anechoic chamber, the result was 0.35g. Upon closer inspection of the refrigerator, the noise originated from the reciprocating compressor where there was interference between the compressor upper shell and the stator frame. To reproduce the compressor problem from the marketplace, a parametric ALT was performed. The failure mode during the ALTs for the compressor was alike to those of the failed refrigerators from the field. As a corrective action, the stator frame in the compressor system was redesigned to increase the minimum gap between the compressor upper shell and the stator frame. During the second ALT, there were no issues. After parameter ALTs were used to develop corrective action plans, the lifetime of the compressor was reassured to have a B1 life 10 years

Artificial Intelligence in Predicting Mechanical Properties of Composite Materials

The determination of mechanical properties plays a crucial role in utilizing composite materials across multiple engineering disciplines. Recently, there has been substantial interest in employing artificial intelligence, particularly machine learning and deep learning, to accurately predict the mechanical properties of composite materials. This comprehensive review paper examines the applications of artificial intelligence in forecasting the mechanical properties of different types of composites. The review begins with an overview of artificial intelligence and then outlines the process of predicting material properties. The primary focus of this review lies in exploring various machine learning and deep learning techniques employed in predicting the mechanical properties of composites. Furthermore, the review highlights the theoretical foundations, strengths, and weaknesses of each method used for predicting different mechanical properties of composites. Finally, based on the findings, the review discusses key challenges and suggests future research directions in the field of material properties prediction, offering valuable insights for further exploration. This review is intended to serve as a significant reference for researchers engaging in future studies within this domain

Improving the Fatigue of Newly Designed Mechanical System Subjected to Repeated Impact Loading

This paper develops parametric accelerated life testing (ALT) as a systematic reliability method to produce the reliability quantitative (RQ) specifications—mission cycle—for recognizing missing design defects in mechanical products as applying the accelerated load, expressed as the inverse of stress ratio, R. Parametric ALT is a way to enhance the prediction of fatigue failure for mechanical systems subjected to repeated impact loading. It incorporates: (1) A parametric ALT plan formed on the system BX lifetime, (2) a fatigue failure and design, (3) customized ALTs with design alternatives, and (4) an assessment of whether the last design(s) of the system fulfills the objective BX lifetime. A BX life concept with a generalized life-stress model and a sample size equation are suggested. A domestic refrigerator hinge kit system (HKS), which was a newly designed mechanical product, was used to illustrate the methodology. The HKS was subjected to repeated impact loading resulting in failure of the HKS in the field. To conduct ALTs, a force and momentum balance was utilized on the HKS. A straightforward impact loading of the HKS in closing the refrigerator door was examined. At the first ALT, the housing of the HKS failed. As an action plan, the hinge kit housing was modified by attaching inside supporting ribs to the HKS to provide sufficient mechanical strength against its loading. At the second ALT, the torsional shaft in the HKS made with austenitic ductile iron (18 wt% Ni) failed. The cracked torsional shaft for the 2nd ALTs came from its insufficient rounding, which failed due to repeated stress. As an action plan, to have sufficient material strength for the repetitive impact loads, the torsional shaft was reshaped to give it more rounding from R0.5 mm to R2.0 mm. After these modifications, there were no problems at the third ALT. The lifetime of the HKS in the domestic refrigerator was assured to be B1 life 10 years

Improving the Fatigue of Newly Designed Mechanical System Subjected to Repeated Impact Loading

This paper develops parametric accelerated life testing (ALT) as a systematic reliability method to produce the reliability quantitative (RQ) specifications—mission cycle—for recognizing missing design defects in mechanical products as applying the accelerated load, expressed as the inverse of stress ratio, R. Parametric ALT is a way to enhance the prediction of fatigue failure for mechanical systems subjected to repeated impact loading. It incorporates: (1) A parametric ALT plan formed on the system BX lifetime, (2) a fatigue failure and design, (3) customized ALTs with design alternatives, and (4) an assessment of whether the last design(s) of the system fulfills the objective BX lifetime. A BX life concept with a generalized life-stress model and a sample size equation are suggested. A domestic refrigerator hinge kit system (HKS), which was a newly designed mechanical product, was used to illustrate the methodology. The HKS was subjected to repeated impact loading resulting in failure of the HKS in the field. To conduct ALTs, a force and momentum balance was utilized on the HKS. A straightforward impact loading of the HKS in closing the refrigerator door was examined. At the first ALT, the housing of the HKS failed. As an action plan, the hinge kit housing was modified by attaching inside supporting ribs to the HKS to provide sufficient mechanical strength against its loading. At the second ALT, the torsional shaft in the HKS made with austenitic ductile iron (18 wt% Ni) failed. The cracked torsional shaft for the 2nd ALTs came from its insufficient rounding, which failed due to repeated stress. As an action plan, to have sufficient material strength for the repetitive impact loads, the torsional shaft was reshaped to give it more rounding from R0.5 mm to R2.0 mm. After these modifications, there were no problems at the third ALT. The lifetime of the HKS in the domestic refrigerator was assured to be B1 life 10 years

Modelling and Simulation of Free Floating Pig for Different Pipeline Inclination Angles

This paper presents a modelling and simulation of free floating pig to determine the flow parameters to avoid pig stalling in pigging operation. A free floating spherical shaped pig was design and equipped with necessary sensors to detect leak along the pipeline. The free floating pig does not have internal or external power supply to navigate through the pipeline. Instead, it is being driven by the flowing medium. In order to avoid stalling of the pig, it is essential to conduct simulation to determine the necessary flow parameters for different inclination angles. Accordingly, a pipeline section with inclination of 0°, 15°, 30°, 45°, 60°, 75°, and 90° were modelled and simulated using ANSYS FLUENT 15.0 with water and oil as working medium. For each case, the minimum velocity required to propel the free floating pig through the inclination were determined. In addition, the trajectory of the free floating pig has been visualized in the simulation

Modelling and Simulation of Free Floating Pig for Different Pipeline Inclination Angles

This paper presents a modelling and simulation of free floating pig to determine the flow parameters to avoid pig stalling in pigging operation. A free floating spherical shaped pig was design and equipped with necessary sensors to detect leak along the pipeline. The free floating pig does not have internal or external power supply to navigate through the pipeline. Instead, it is being driven by the flowing medium. In order to avoid stalling of the pig, it is essential to conduct simulation to determine the necessary flow parameters for different inclination angles. Accordingly, a pipeline section with inclination of 0°, 15°, 30°, 45°, 60°, 75°, and 90° were modelled and simulated using ANSYS FLUENT 15.0 with water and oil as working medium. For each case, the minimum velocity required to propel the free floating pig through the inclination were determined. In addition, the trajectory of the free floating pig has been visualized in the simulation