Advanced Computer-aided Engineering Research Articles

Structural strength analysis of a rotary drum mower during harvesting

A Rotary Drum Mower (RDM) is a tractor-mounted mechanism used for harvesting green fodder crops. It faces dynamic forces from rough field surfaces and cutting resistance, posing design challenges and potential failures. This study aims to present a well-designed procedure for analysing the structural strength of an RDM during harvesting, employing both experimental and engineering simulation methods. A specific harvesting scenario was created to simulate realistic load conditions. Experimental testing and advanced computer-aided engineering (CAE) simulations were conducted. Tractor Power Take-off (PTO) torque measurements during harvesting revealed values of 231.07 Nm, 264.44 Nm, and 269.39 Nm at speeds of 8.56 km h-1, 12.6 km h-1, and 16.23 km h-1, respectively. Finite element analysis (FEA) was conducted to determine stress levels in the RDM components (RDM165-A-004, RDM165-B-003, and RDM165-B-004). The FEA stress results ranged from 5.070 MPa to 20.600 MPa, 13.800 MPa to 28.600 MPa, and 5.400 MPa to 27.550 MPa, respectively. Experimental testing yielded stress results ranging from 2.127 MPa to 18.600 MPa, 14.618 MPa to 33.229 MPa, and 8.838 MPa to 31.248 MPa, respectively. The comparison between experimental and FEA results showed reasonable correlation. FEA visual outputs provided insights into the maximum equivalent stress and deformation distributions on the RDM, with no indications of failure in the machine's structure observed in either the experimental or numerical analyses. In conclusion, this study demonstrates that the machine analysed operates safely under harvesting conditions. Moreover, the combination of experimental and advanced CAE methodologies presented in this research offers a valuable approach for future investigations into the complex stress and deformation evaluations of rotary drum mowers.

Finite element analysis megatrends: A road less traveled

AbstractIn today's environment, finite element analysis is crucial for Mechanical Engineers. In today's highly competitive industries, graduates need to be productive from Day one as they enter the industry. To meet the vast range of industrial requirements or even for higher education, education institutes must adhere to an industry enabled curriculum as defined in collaboration with industry employees. As students reach their prefinal year of mechanical engineering studies, they will encounter courses like finite element analysis, design of machine elements, and failure analysis in design, which will serve as foundation steps for their future careers. As students need to compete in the real world, it becomes imperative to have a thorough understanding of both theoretical and practical issues. The focus of current work is to provide them a platform to think as a real‐time problem‐solving engineer to address the society‐based problems and how he/she approaches the problem in an optimized way and finally, convert the entire work to tangible documents in the form of research articles. Since 2018, a new vertical called as “advanced computer aided engineering (CAE)” has emerged to link and prepare people for the business. In the realm of finite element method (FEM) theoretical and allied laboratory work, the current study discusses sustainability while selecting the problem statement. The entire emphasis is on eco‐environment with nature's sustainability along with the go‐green concept in terms of materials, design, optimization, cost, quality, and so on. The present work includes several new features that were not present in the previous curriculum, such as transforming the work to high‐quality journals, student feedback, subscription‐based journal selection for the manuscript, and embedding experimental and analytical work alongside simulation studies. This time, 40 teams participated, with around 36 project works being qualified for publication in prestigious journals and 8–10 works being filed for Indian patents. In terms of quality and quantity of work completed, this is the best output attained in contrast to previous iterations. Because of the increasing growth rate of higher education, our students have been able to get into Top 100 QS ranked universities. The figures show that because of faculty involvement in the FEM lab, Advanced CAE I, and Advanced CAE II, over the previous 4–5 years, students were able to publish more than 50 publications in prestigious peer‐reviewed International/National Journals and Conference papers.

Strength-based design of a sunflower stalk cutter machine design using finite element analysis and experimental validation

In this study, the total algorithm of the strength-based design of the system for mass production has been developed. The proposed algorithm, which includes numerical, analytical, and experimental studies, was implemented through a case study on the strength-based structural design and fatigue analysis of a tractor-mounted sunflower stalk cutting machine (SSCM). The proposed algorithm consists of a systematic engineering approach, material selection and testing, design of the mass criteria suitability, structural stress analysis, computer-aided engineering (CAE), prototype production, experimental validation studies, fatigue calculation based on an FE model and experimental studies (CAE-based fatigue analysis), and an optimization process aimed at minimum weight. Approximately 85% of the system was designed using standard commercially available cross-section beams and elements using the proposed algorithm. The prototype was produced, and an HBM data acquisition system was used to collect the strain gage output. The prototype produced was successful in terms of functionality. Two- and three-dimensional mixed models were used in the structural analysis solution. The structural stress analysis and experimental results with a strain gage were 94.48% compatible in this study. It was determined using nCode DesignLife software that fatigue damage did not occur in the system using the finite element analysis (FEA) and experimental data. The SSCM design adopted a multi-objective genetic algorithm (MOGA) methodology for optimization with ANSYS. With the optimization solved from 422 iterations, a maximum stress value of 57.65 MPa was determined, and a 97.72 kg material was saved compared to the prototype. This study provides a useful methodology for experimental and advanced CAE techniques, especially for further study on complex stress, strain, and fatigue analysis of new systematic designs desired to have an optimum weight to strength ratio.

Computationally efficient evaluation of fuel and electrical energy economy of plug-in hybrid electric vehicles with smooth driving constraints

Advanced computer-aided engineering tools are urgently needed to foster the development of electrified road vehicles that would enable abating fuel consumption and pollutant emissions of the transport sector. Concerning plug-in hybrid electric vehicles (HEVs), implementing an energy management strategy that can rapidly estimate near-optimal powertrain control trajectories while effectively dealing with broaded battery state-of-charge (SOC) window utilization and smooth HEV driving requirements still needs extensive development. To overcome the highlighted drawback, this paper introduces a formulation of the slope-weighted energy-based rapid control analysis (SERCA) algorithm which can rapidly identify near-optimal plug-in HEV control trajectories while complying with SOC boundaries and limiting the number of thermal engine activations and gear shifts. The HEV numerical model is introduced first, followed by formulating the optimal plug-in HEV control problem with smooth driving constraints and describing the dedicated SERCA based control approach. A performed case study demonstrates that SERCA can identify smooth driving constrained near-optimal HEV control trajectories for a 1.5 hours-long real-world driving mission within two minutes on a desktop computer, while a global optimal control approach such as dynamic programming (DP) is found to require more than 10 hours to perform the same task. On the other hand, compared with the global optimal reference provided by DP, the increase in estimated plug-in HEV operative cost in terms of fuel and electrical energy consumption associated to SERCA is always contained within few percentage points. The proposed methodology can accelerate HEV powertrain design and on-board supervisory controller development procedures.

Investigation and optimization for the dynamical behaviour of the vehicle structure

Conceptual modelling is known as a well suited alternative approach for Computer-Aided Engineering (CAE) analysis in automotive industry. In this paper, an improved conceptual modelling method in which beams and panels of the structure are modelled as simplified beam elements has been proposed. To explore the advantage of conceptual modeling in determining the resonant frequencies/mode-shapes, a case study for wheelhouse was performed. Firstly, an experimental test and advanced CAE analysis were carried out to measure the wheelhouse dynamic characteristics. The advanced CAE model was then validated by means of Modal Assurance Criterion and natural frequencies by associated experimental measurements. The results of wheelhouse concept model compared to the advanced CAE and experimental model in low frequency range, showed that the error percent of natural frequency is lower than 10% and the Modal Assurance Criterion is above 0.75 for the first four mode shapes of wheelhouse structure. Finally, the conceptual model is used as a baseline for optimization. The genetic algorithm was implemented to maximize the first natural frequency to 41.74 Hz. So The genetic algorithm successfully provided new possibility for optimization by attempting to influence the first mode shape by means of the cross section characteristics. Due to the accuracy and reliability of developed conceptual model, this modelling approach can be a crucial tool in CAE and vibration analysis of vehicle in the early design phase. The proposed method allows the designer to give the results of design changes very quickly by neglecting details. Therefore, for the analysis of the vehicle performance in NVH domain, the proposed method could be considered in the conceptual design phase.

Vehicle Concept Modeling: A New Technology for Structures Weight Reduction

The lightening of the vehicle body structure generally aggravates the noise vibration and harshness (NVH) and the crash performances of the vehicle. The development and application of the vehicle advanced computer aided engineering (CAE) allowed the vehicle designers to considerably reduce the weight and improve the structural performance of the body. However, the current advanced (detailed) CAE model can only be available in the late design phase of the vehicle when only minor changes of the structure is feasible. Unlike the detailed CAE model, which requires all detailed design, the concept CAE model can be created without any need to the detailed CAD data and it can be created in the early (concept) design phase. Accordingly, in this paper, a concept modeling method is presented for a sedan car. This model represents the major structural dynamic characteristics of the body and enables the designers to optimize the structure in terms of the performances and mass in early design phase. The detailed CAE model of the body-in-white (BIW) of vehicle is reduced to a beam elements concept-structure so that the concept structure has similar structural dynamics behavior with the corresponding test data. The developed CAE concept model demonstrates a robust method to enhance the NVH and crash performances in early stage of design. The proposed method can be used to effectively predict and optimize the vehicle body structure and support body lightweighting design process. The reduction of BIW mass will ultimately reduce fuel consumption leading to energy efficiency and reduced pollution.

On the selection of the mode cut-off number in component mode reduction

Dynamic analysis of very large and complicated FE structures such as FE full-vehicle structures are mainly performed with synthesized, component mode-reduced sub-models with common interfaces. The theory of component mode reduction (CMR) is well known, but it is not a simple application in real-live analyses. One of its problems, discussed in this paper, has not appeared in literature or in commercial software releases and their reference guides yet, although, in advanced computer-aided engineering, most dynamic analysts are confronted with it. The problem is related to the mode cut-off number in CMR and its enormous influence on the components reduced representation and the response solution. The mode cut-off number is the number of retained mode shapes from the components in CMR and the frequency corresponding to the highest mode is called the cut-off frequency. Ultimately the response quantities in excited vibrations, predicted from the reduced order model, are only as good as the component modes and the system modes. A proper application of the CMR technique is one of the most important success factors in today’s analysis quality in the advanced product development process across many industries. Therefore, the mode cut-off number should be considered to be a measure of analysis quality. The paper illustrates the effect of the mode cut-off number in an example from automotive industry: CMR of a body-in-white component and system mode computation of the reduced system. A list of guide lines concludes the discussion and some proposals for a stable analysis process and optimal performance are also given.

Developments in interdisciplinary simulation and design software for mechanical systems

Software for interdisciplinary simulation and design of mechanical systems is emerging as a broadly applicable computer-aided engineering (CAE) tool. The emergence of powerful graphics based workstations, affordable minisuper computers, and network computing systems enhances the potential of this class of advanced CAE tools for use in a broad range of industrial applications. This paper analyzes the potential that exists for creating advanced CAE tools by (1) defining requirements for an advanced interdisciplinary simulation and design software system, including system executives, application program integration, support utilities, user interfaces, data base management systems, and computer environment; (2) giving an overview of interdisciplinary systems that are currently in use or in development; and (3) reviewing important features of existing interdisciplinary software systems, with respect to requirements for an advanced CAE system.