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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.

Background/purpose: Additive manufacturing (AM), also known as 3D printing, has the potential to transform the industry. While there have been advancements in using AM for dental restorations, there is still a need for further research to develop functional biomedical and dental materials. It’s crucial to understand the current status of AM technology and research trends to advance dental research in this field. The aim of this study is to reveal the current status of international scientific publications in the field of dental research related to AM technologies. Materials and methods: In this study, a systematic scoping review was conducted using appropriate keywords within the scope of international scientific publishing databases (PubMed and Web of Science). The review included related clinical and laboratory research, including both human and animal studies, case reports, review articles, and questionnaire studies. A total of 187 research studies were evaluated for quantitative synthesis in this review. Results: The findings highlighted a rising trend in research numbers over the years (From 2012 to 2022). The most publications were produced in 2020 and 2021, with annual percentage increases of 25.7% and 26.2%, respectively. The majority of AM-related publications in dentistry research originate from Korea. The pioneer dental sub-fields with the ost publications in its category are prosthodontics and implantology, respectively. Conclusion: The final review result clearly stated an expectation for the future that the research in dentistry would concentrate on AM technologies in order to increase the new product and process development in dental materials, tools, implants and new generation modelling strategy related to AM. The results of this work can be used as indicators of trends related to AM research in dentistry and/or as prospects for future publication expectations in this field.

Potato bruising resulting from mechanical impact during production operations including harvest and postharvest is a significant concern within the potato production sector, leading to consumer complaints and economic losses. The detection of instantaneous internal bruising poses a particular challenge as it can progress over time during storage or transportation, making it difficult to identify immediately after external impact. This study aims to investigate the progression of bruising and accurately represent the instantaneous dynamic deformation behavior of potato tubers under four pendulum bob impact cases (pendulum arm angles of 30°, 45°, 60°, and 90°). To analyze the dynamic impact deformation characteristics of the tubers, solid modeling based on a reverse engineering approach and explicit dynamic engineering simulations were employed. The simulation results yielded valuable numerical data and visual representation of the deformation progression. The loading conditions considered in this study indicated that the maximum stress values, reaching 0.818 MPa at a pendulum arm angle of 90°, remained below the bio-yield stress point of the tuber flesh (1.05 MPa) determined through experimental compression tests. Therefore, it was concluded that the impact did not cause permanent deformation (i.e., permanent bruising) in the tuber. However, the numerical analysis clearly demonstrated the sequence of stress occurrences, which is a key contributing factor to potential permanent bruising. In this regard, the bruising energy threshold of 318.314 mJ (R2: 0.96) was extrapolated. The numerical findings presented in this study can aid in evaluating the susceptibility of tuber samples to bruising. By employing nonlinear explicit dynamics simulations, this research contributes to the advancement of understanding complex deformation and bruising in solid agricultural products. Moreover, the application of these techniques holds significant industrial implications for enhancing

This study focuses on the structural design analysis of a cura baglama, a traditional Turkish string instrument that does not have in place a regulated set of manufacturing standards to follow. The aim therefore is to introduce a structural deformation analysis for a sample cura baglama in three different string tensions via a numerical method-based engineering analysis technique. The three-dimensional solid model of a sample cura baglama was created using a 3D scanner and parametric 3D solid modelling software. Based on experimental frequency analysis, structural deformation analyses of the instrument were conducted using finite element method-based engineering simulation techniques. The simulation results revealed useful visual and numerical outputs related to the deformation behaviour of the instrument under pre-defined boundary conditions. A maximum deformation of 0.223 mm on the soundboard (at the D3 tune) and a maximum equivalent stress of 18.325 MPa on the bridge (at the D3 tune) were calculated. The outputs of this research contribute to further research into the usage of numerical method-based deformation simulation studies related to the standardisation, development, and preservation of such traditional string instruments.

A rotary drum mower is a tractor-mounted harvester used for harvesting green fodder plants in agricultural fields. During transportation, it experiences significant dynamic road reaction forces that can cause deformation and functional failures. This study focuses on analysing the deformation behaviour of the machine during transportation to test the machine’s failure condition. To conduct the strength analysis, a total work cycle scenario reflecting actual load conditions and design challenges was created. Experimental strain-gauge-based stress analysis and advanced computer-aided engineering (CAE) simulation methods were employed. The study successfully conducted experimental stress analysis, 3D solid modelling, and validated finite element analysis (FEA). A comparison between experimental and simulation results showed an average relative difference of 24.25% with a maximum absolute difference of approximately 5 MPa. No functional failure issues were observed during physical experiments. The study also revealed that the mean dynamic loading value, when compared to the static linkage position, was calculated as 3.65 ± 0.40. Overall, this research provides a valuable approach for future studies on complex stress and deformation evaluations of agricultural machinery and equipment.

Malleolar screw fixation is the most widely used treatment method for medial malleolar (MM) fractures. Here, although buttress plate fixation is advocated for vertical MM fractures, the angular discrimination between oblique and vertical MM fractures is still not fully understood. The purpose of this study is to test the adequacy of screw fixation in MM fractures with different angles and determination of a ‘critical fracture angle’ to guide surgeons in the decision-making for screw fixation for MM fractures by utilising an advanced engineering simulation approach. In addition to loading of the healthy tibia structure, various cases of the MM fracture double screw fixation (14 simulation scenarios in total with fracture angles between 30° and 90°, in 5° increments) were considered in this research and their static loading conditions just after fixation operation were simulated through nonlinear (geometric and contact nonlinearity) finite element analysis (FEA). Patient-specific computed tomography scan data, parametric three-dimensional solid modelling and finite element method (FEM) based engineering codes were employed in order to simulate the fixation scenarios. Visual and numerical outputs for the deformation and stress distributions, separation and sliding behaviours of the MM fracture fragments of various screw fixations were clearly exhibited through FEA results. Minimum and maximum separation distances (gap) of 3.75 µm and 150.34 µm between fracture fragments at fracture angles of 30˚ and 90˚ were calculated respectively against minimum and maximum sliding distances of 25.87 µm and 41.37 µm between fracture fragments at fracture angles of 90˚ and 35˚ respectively. The FEA results revealed that while the separation distance was increasing, the sliding distance was decreasing and there were no distinct differences in sliding distances in the scenarios from fracture angles of 30° to 90°. The limitations and errors in a FEA study are inevitable, however, it was

Background: Antero-medialisation osteotomy combined with a distalisation procedure may require a more stable fixation as the osteotomy fragment loses both proximal and distal support. This finite element analysis aimed to compare the mechanical behaviour of different fixation techniques in tibial tubercle antero-medialisation osteotomy combined with distalisation procedure. Methods: Tibial tubercle osteotomy combined with distalisation was modelled based on computerised tomography data, which were acquired from a patient with patellar instability requiring this procedure. Six different fixation configurations with two 3.5-mm cortical screws (1), two 4.5-mm cortical screws (2), three 3.5-mm cortical screws (3), three 4.5-mm cortical screws (4), three 3.5-mm screws with 1/3 tubular plate (5), and four 3.5-mm screws with 1/3 tubular plate (6) were created. A total of 1654 N of force was applied to the patellar tendon footprint on the tibial tubercle. Sliding, gap formation, and total deformation between the osteotomy components were analyzed. Results: Maximum sliding (0.660 mm), gap formation (0.661 mm), and displacement (1.267 mm) were seen with two 3.5-mm screw fixation, followed by two 4.5-mm screws, three 3.5-mm screws, and three 4.5-mm screws, respectively, in the screw-only group. Overall, the minimum displacement was observed with the four 3.5-mm screws with 1/3 tubular plate fixation model. Conclusions: Plate fixation might be recommended for tibial tubercle antero-medialisation osteotomy combined with distalisation procedure because it might allow early active range of motion exercises and weight-bearing.

Introduction: Finite element analysis (FEA) is a numerical procedure utilised in the engineering analysis of structures and is one of the most common numerical methods utilised in many research activities in dentistry such as implantology, prosthodontics and restoration. FEA can be considered a useful tool in order to describe the deformation aspects of dental components that cannot be measured easily by in vivo models. The geometry, material properties, finite element model (mesh structure) and boundary conditions defined for a particular FEA setup are the factors affecting the accuracy of the results of a FEA. Most especially, material models employed in FEA play a critical role, however, the literature cannot provide standard material models and data in agreement to be defined in the FEA studies handled specifically for human teeth. The aim of this study is reviewing the most utilised data related to material properties (limited to linear homogeneous isotropic material model) of the tooth components, evaluate the sources and reasons for the different values defined in dental research and provide filtered material data which can be utilised in related FEA studies. Material and methods: Electronic databases (PubMed and Web of Science) were reviewed for publications on FEA utilised in dentistry research. 155 research publications in total were considered in this paper. The search keywords of “finite element analysis”, “finite element study”, “mechanical properties” and “teeth” were combined through Boolean operators. The primary question under review was: “How were the material properties of the tooth components and numerical ranges, which are assigned in a FEA utilised in dental research, obtained and verified?”. Results: It was possible to determine sixteen different elastic modulus (EM) and seven Poisson’ ratio (PR) values for enamel, eighteen EM and five PR values for dentin, sixteen EM and four PR values for periodontal ligament, eight EM and one PR values for

Malleolar screw fixation is the most widely used treatment method for medial malleolar (MM) fractures. Here, although buttress plate fixation is advocated for vertical MM fractures, the angular discrimination between oblique and vertical MM fractures is still not fully understood. The purpose of this study is to test the adequacy of screw fixation in MM fractures with different angles and determination of a ‘critical fracture angle’ to guide surgeons in the decision-making for screw fixation for MM fractures by utilizing an advanced engineering simulation approach. In addition to loading of the healthy tibia structure, various cases of the MM fracture double screw fixation (14 simulation scenarios in total with fracture angles between 30° and 90°, in 5° increments) were considered in this research and their static loading conditions just after fixation operation were simulated through nonlinear (geometric and contact nonlinearity) finite element analysis (FEA). Patient-specific computed tomography scan data, parametric three-dimensional solid modelling and finite element method (FEM) based engineering codes were employed in order to simulate the fixation scenarios. Visual and numerical outputs for the deformation and stress distributions, separation and sliding behaviours of the MM fracture fragments of various screw fixations were clearly exhibited through FEA results. Minimum and maximum separation distances (gap) of 3.75 and 150.34 µm between fracture fragments at fracture angles of 30° and 90° were calculated respectively against minimum and maximum sliding distances of 25.87 and 41.37 µm between fracture fragments at fracture angles of 90° and 35°, respectively. The FEA results revealed that while the separation distance was increasing, the sliding distance was decreasing and there were no distinct differences in sliding distances in the scenarios from fracture angles of 30°–90°. The limitations and errors in a FEA study are inevitable, however, it was interpre

This study aimed to evaluate different fixation techniques and implants in oblique and biplanar chevron medial malleolar osteotomies using finite element analysis. Both oblique and biplanar chevron osteotomy models were created, and each osteotomy was fixed with two different screws (3.5 mm cortical screw and 4.0 mm malleolar screw) in two different configurations; (1) two perpendicular screws, and (2) an additional third transverse screw. Nine simulation scenarios were set up, including eight osteotomy fixations and the intact ankle. A bodyweight of 810.44 N vertical loading was applied to simulate a single leg stand on a fixed ankle. Sliding, separation, frictional stress, contact pressures between the fragments were analyzed. Maximum sliding (58.347µm) was seen in oblique osteotomy fixed with two malleolar screws, and the minimum sliding (17.272 µm) was seen in chevron osteotomy fixed with three cortical screws. The maximum separation was seen in chevron osteotomy fixed with two malleolar screws, and the minimum separation was seen in oblique osteotomy fixed with three cortical screws. Maximum contact pressure and the frictional stress at the osteotomy plane were obtained in chevron osteotomy fixed with three cortical screws. The closest value to normal tibiotalar contact pressures was obtained in chevron osteotomy fixed with three cortical screws. This study revealed that cortical screws provided better stability compared to malleolar screws in each tested osteotomy and fixation configuration. The insertion of the third transverse screw decreased both sliding and separation. Biplanar chevron osteotomy fixed with three cortical screws was the most stable model.

Objectives: The aim of this study was to investigate the effect of cartilage thickness mismatch on tibiotalar articular contact pressure in osteochondral grafting from femoral condyles to medial talar dome using a finite element analysis (FEA). Materials and methods: Flush-implanted osteochondral grafting was performed on the talar centromedial aspect of the dome using osteochondral plugs with two different cartilage thicknesses. One of the plugs had an equal cartilage thickness with the recipient talar cartilage and the second plug had a thicker cartilage representing a plug harvested from the knee. The ankle joint was loaded during a single-leg stance phase of gait. Tibiotalar contact pressure, frictional stress, equivalent stress (von Mises values), and deformation were analyzed. Results: In both osteochondral grafting simulations, tibiotalar contact pressure, frictional stress, equivalent stress (von Mises values) on both tibial and talar cartilage surfaces were restored to near-normal values. Conclusion: Cartilage thickness mismatch does not significantly change the tibiotalar contact biomechanics, when the graft is inserted flush with the talar cartilage surface.

This study describes a strength-based design analysis protocol by means of finite element analysis (FEA) for a damaged engine mounting bracket in a converted electric vehicle. The mounting bracket considered in the study is a product specifically designed and manufactured for a converted electric vehicle and failed during conventional operation of the vehicle. Thus, design improvement/revision (redesign) on the bracket geometry was investigated. In this context, to prevent such undesired failures, strength-based design features such as deformation behaviour and stress distribution under projected loads on the bracket should be properly described; however, an accurate description of these features of the bracket may become a complex experimental problem to be solved by designers. This study described redesign of the strength-based design features of the engine mounting bracket through finite element analysis under torsional loading generated by the electric engine that was determined to be the reason for the failure and thus the motivation to realise a safer design. Visual and numerical results obtained from the simulation revealed a clear understanding of the failure behaviour of the bracket and therefore enabled an informed approach to the redesign stage. The initial FEA of the part design mapped the damage regions on the part geometry and indicated the stress magnitudes that were more than the material’s stress limits. The comparison of the failure plots and numerical data obtained from this initial FEA and physically damaged part was consistent. This concluded that the FEA satisfactorily exhibited the deformation behaviour and the main reason for the failure was insufficient geometry thickness and notch effect against predefined loading conditions. Therefore, the main design improvement was realised on these geometric features. Subsequently, the final FEA highlighted that the redesign would enable safe operation. This work contributes to further research into usa

In musical instruments, the geometric design and material features of the instrument are the most important factors that determine the sound characteristics of the instrument. Traditional replication and experiment-based handcrafting methods are predominant in the production of Turkish Folk Music wind instruments. The instrument manufacturing and standardization approaches, which include the relevant rules of physics and engineering practices, are limited purely to prototype studies for scientific research purposes. It is almost impossible to find studies on Turkish Folk Music wind instrument design and production involving computer aided design and engineering applications. In this study, an example Turkish woodwind instrument, the Turkish Treble Recorder (dilli kaval) is considered, and the air flow behaviour and acoustic (sound) power magnitudes that occur at different air flow rates are simulated in a computer environment using a Computational Fluid Dynamics (CFD) simulation technique. In the study, numerical and visual outputs related to air behaviour at different air flow rates that may be used in the instrument manufacturing phases were obtained. Acoustic power level was also measured experimentally. Simulation outputs (the acoustic power level) were compared to experimental results in order to validate the simulation results. The comparison revealed that the highest relative difference was calculated as 13.32(%). This value indicated that the simulation results were reasonably consistent with the results of the experimental measurement. Additionally, this study was constructed as a case study that may provide reference for future research studies in this field.

The bruising phenomenon of apple fruit under impact loading is still a very important problem to be solved in order to design optimal harvest and processing systems and for ensuring the quality of the fruit during long-term periods of storage. This study focused on deformation simulation of apples (cv. ’Pink Lady’) under dynamic impact loading during drop tests in order to describe time-dependent bruising occurrence and the bruising effect on the postharvest fruit quality during long-term storage. In the study, analytical, experimental methods and finite element analysis based explicit dynamics simulation techniques were employed. Three drop heights (250 mm, 500 mm and 750 mm) and three impact materials (structural steel, high-density polyethylene and wood) and single fruit orientation (transverse) for the drop tests were considered. Experimental drop test, physical and chromatographic analyses at the time of harvest (first testing day) and during storage periods of 30, 120 and 210 days were realised. Physical and chromatographic analyses revealed that damaged apples lost a greater amount of weight when considering the increase in drop height. Furthermore, bruised surfaces of apples lost their luminosity just after the drop test. Ethylene production and respiration rates rapidly increased just after the fruit bruising and this increase was correlated with the drop height. Additionally, material tests revealed the yield stress point of the apple as 0.385 MPa and the simulation results provided useful visuals and numerical data related to the time-dependent bruising phenomenon. The validation study on the experimental and simulation setup revealed that bruising surface area is a more accurate measurement than bruise volume when evaluating bruising on the fruit flesh through a numerical method-based simulation study (average relative difference: 5.5%).

This study aimed to evaluate different fixation techniques and implants in oblique and biplanar chevron medial malleolar osteotomies using finite element analysis. Both oblique and biplanar chevron osteotomy models were created, and each osteotomy was fixed with two different screws (3.5 mm cortical screw and 4.0 mm malleolar screw) in two different configurations; (1) two perpendicular screws, and (2) an additional third transverse screw. Nine simulation scenarios were set up, including eight osteotomy fixations and the intact ankle. A bodyweight of 810.44 N vertical loading was applied to simulate a single leg stand on a fixed ankle. Sliding, separation, frictional stress, contact pressures between the fragments were analyzed. Maximum sliding (58.347µm) was seen in oblique osteotomy fixed with two malleolar screws, and the minimum sliding (17.272 µm) was seen in chevron osteotomy fixed with three cortical screws. The maximum separation was seen in chevron osteotomy fixed with two malleolar screws, and the minimum separation was seen in oblique osteotomy fixed with three cortical screws. Maximum contact pressure and the frictional stress at the osteotomy plane were obtained in chevron osteotomy fixed with three cortical screws. The closest value to normal tibiotalar contact pressures was obtained in chevron osteotomy fixed with three cortical screws. This study revealed that cortical screws provided better stability compared to malleolar screws in each tested osteotomy and fixation configuration. The insertion of the third transverse screw decreased both sliding and separation. Biplanar chevron osteotomy fixed with three cortical screws was the most stable model.

During the coronavirus disease-19 pandemic, the demand for specific medical equipment such as personal protective equipment has rapidly exceeded the available supply around the world. Specifically, simple medical equipment such as medical gloves, aprons, goggles, surgery masks, and medical face shields have become highly in demand in the health-care sector in the face of this rapidly developing pandemic. This difficult period strengthens the social solidarity to an extent parallel to the escalation of this pandemic. Education and government institutions, commercial and noncommercial organizations and individual homemakers have produced specific medical equipment by means of additive manufacturing (AM) technology, which is the fastest way to create a product, providing their support for urgent demands within the health-care services. Medical face shields have become a popular item to produce, and many design variations and prototypes have been forthcoming. Although AM technology can be used to produce several types of noncommercial equipment, this rapid manufacturing approach is limited by its longer production time as compared to conventional serial/mass production and the high demand. However, most of the individual designer/maker-based face shields are designed with little appreciation of clinical needs and nonergonomic. They also lack of professional product design and are not designed according to AM (Design for AM [DfAM]) principles. Consequently, the production time of up to 4 – 5 h for some products of these designs is needed. Therefore, a lighter, more ergonomic, single frame medical face shield without extra components to assemble would be useful, especially for individual designers/makers and noncommercial producers to increase productivity in a shorter timeframe. In this study, a medical face shield that is competitively lighter, relatively more ergonomic, easy to use, and can be assembled without extra components (such as elastic bands, softening materia

As a branch of the global machinery industry, the agricultural (farm) machinery design and manufacturing or agricultural engineering industry has become one of the most important industries to be supported and focussed on in the era of hunger threats foreseen in the World’s future. In order to produce sufficient volumes of food from current limited agricultural land, well-designed machinery and high technology-supported mechanisation of the agricultural production processes is a vital necessity. However, although novel improvements are observed in this area, they are very limited. There is a lack of implementation of advanced engineering design and manufacturing technologies in this industry, therefore agricultural engineering could be considered a potential engineering research area with this in mind. This study aims to highlight the potential, gaps, sector specific challenges and limitations of the agricultural engineering research area at a macro level. Under consideration of the sector-specific indicators, the study revealed a major result: there is an insufficient level of sector-specific research on implementation strategies for up-to-date design and manufacturing technologies.

Additive Manufacturing can be described as a process to make 3D objects by adding layer upon layer of material, the material traditionally being plastics, metals or ceramics, however ‘smart’ materials are now in use. Nowadays, the term “3D Printing” has become a much-used synonym for additive manufacturing. The use of computing, 3D solid modelling applications, layering materials and machine equipment is common to majority of additive manufacturing technologies. Advancing from this 3D printing technology, is an emerging trend for what is being termed “4D printing”. 4D printing places dependency on smart materials, the functionality of additive manufacturing machines and in ingenious design processes. Although many developments have been made, limitations are still very much in existence, particularly with regards to function and application. The objective of this short review is to discuss the developments, challenges and outlook for 4D printing technology. The review revealed that 4D printing technology has application potential but further research work will be vital for the future success of this technology. Katmanlı imalat; üç boyutlu objelerin uygun malzemeler kullanılarak katman-katman inşa edilmesi süreci olarak tanımlanabilmektedir. Genellikle kullanılan malzemeler plastik, metal veya seramikler olmakla birlikte son günlerde akıllı malzemelerinde bu teknolojide yer aldığı görülmektedir. Günümüzde yaygınlaşan bu teknolojide “üç boyutlu yazdırma (3D Printing)” kavramı genel terminoloji olan “katmanlı imalat” yerine de kullanılabilmektedir. Nümerik hesaplama yöntemleri, üç boyutlu katı modelleme uygulamaları, katman imalatta kullanılan malzemeler, bu işlemlerde yer alan makine elemanları/sistemleri katmanlı imalat teknolojilerinin başlıca gereklilikleri arasında yer almaktadır ve gün geçtikçe bu alanlarda yeni teknolojik gelişmeler görülmektedir. Bu bağlamda üç boyutlu yazdırma kavramının ötesinde ileri düzey teknoloji eğilimi ile yeni bir kavram olan “dört boy

This paper focuses on a design analysis of a flat die used in an agricultural biomass pelletizing machine by considering its high pressure loading failure susceptibility. The pellet die is one of the key elements in a pelletizing machine, and the strength of the die plate has an important role on the pellet’s quality and producibility. In fact, higher compression ratio (CR - the ratio of effective length and the internal (press channel) diameter of a die orifice/hole) will provide denser pellets which is a desired phenomenon, however, if the compression pressure is too high or CR is not determined to compensate high pressures, the raw material may block the die and the die may experience deformation failure due to overloading. If the desire is to make high quality pellets with no die failure, optimum flat die hole/orifice design parameters should be used which can provide the best CR for a specific compression pressure. This is the core motivation of this research. In this study, Finite Element Analysis (FEA) based design exploration has been utilised for a sample single hole flat die with various die geometry parameters against various compression pressure values. Following the FEA design exploration undertaken, a response surface analysis (RSA) was carried out and then estimation models (empirical equations), which could be used to calculate parameters of the die hole/orifice against applied compression pressure and failure susceptibility based on structural stress and deformation, was described. The results gained from the RSA has indicated that the estimation models have high R2 values (higher than 98 %) which could be used for adequately predicting failure susceptibility indicators. In addition to this, FEM-based simulation print-outs have provided useful stress distribution visuals on the die against different compression pressure values. Most especially, the study has highlighted that a detailed structural optimisation study may be scheduled in order to obtai

Additive Manufacturing can be described as a process to build 3D objects by adding layer-upon-layer of material, the material traditionally being plastics, metals or ceramics, however ‘smart’ materials are now in use. Nowadays, the term “3D Printing” has become a much-used synonym for additive manufacturing. The use of computing, 3D solid modeling applications, layering materials and machine equipment is common to majority of additive manufacturing technologies. Advancing from this 3D printing technology, is an emerging trend for what is being termed “4D printing”. 4D printing places dependency on smart materials, the functionality of additive manufacturing machines and in ingenious design processes. Although many developments have been made, limitations are still very much in existence, particularly with regards to function and application. The objective of this short review is to discuss the developments, challenges and outlook for 4D printing technology. The review revealed that 4D printing technology has application potential but further research work will be vital for the future success of 4D printing.

Realistic representation of time-dependent internal stress progression and deformation behaviour of a potato tuber during a sample drop case has been studied in this paper. A reverse engineering approach, compressive tests, slow motion camera records and finite element analysis (FEA) were employed to analyse the drop case deformation behaviour of a sample potato tuber. Simulation results provided useful numerical data and stress distribution visuals. The numerical results are presented in a format that can be used for the determination of bruise susceptibility magnitude on solid-like agricultural products during drop case. The visual observations revealed that slow motion camera images and simulation printouts were in good correlation. The modulus of elasticity of the potato specimens was calculated from experimental data to be 3.12 [MPa] and simulation results showed that the maximum equivalent stress was 0.526 [MPa] on the tuber. This value for stress indicates that bruising is not likely on the tuber under a pre-defined drop height. In order to test the simulation accuracy, empirical and simulation-based estimates for total energy in this drop case were compared. The relative difference between empirical and simulation results was 1.27 %. This study provide a good “how to do” guide to further research on the utilisation of (FEM)-based time-dependent simulation approach in complex mechanical impact based damaging analyses and industry focused applications related to solid-like agricultural products such as potato.

This study focuses on determining internal stress progression and the realistic representation of time dependent deformation behaviour of potato tubers under a sample mechanical collision case. A reverse engineering approach, physical material tests and finite element method (FEM)-based explicit dynamics simulations were utilised to investigate the collision based deformation characteristics of the potato tubers. Useful numerical data and deformation visuals were obtained from the simulation results. The numerical results are presented in a format that can be used for the determination of bruise susceptibility magnitude on solid-like agricultural products. The modulus of elasticity was calculated from experimental data as 3.12 [MPa] and simulation results showed that the maximum equivalent stress was 1.40 [MPa] and 3.13 [MPa] on the impacting and impacted tubers respectively. These stress values indicate that bruising is likely on the tubers. This study contributes to further research on the usage of numerical-methods-based nonlinear explicit dynamics simulation techniques in complicated deformation and bruising investigations and industrial applications related to solid-like agricultural products.

This study describes a finite element method (FEM) based deformation simulation procedure for a power take off (PTO) shaft in an agricultural tractor. The agricultural tractor is a mobile power source in agricultural fields. The Agricultural tractor transmits power to the working implement through several systems independently. Most especially, rotary elements used in agricultural machinery take the required power and movement from the tractor take off (PTO) shaft. During this operation, the PTO shaft experiences a high dynamic loading condition such as excessive instant (impact) loading. This may cause an undesired failure case for the PTO shaft. In order to prevent such undesired failures, loading condition and stress distribution on the component should be described properly, however, an accurate description of the structural stress distribution on the shaft becomes an important problem. In this content, a case study was carried out on a failed PTO shaft, as described in this paper. The aim of this case study is to exhibit the stress distribution on the PTO shaft through finite element analysis under a torsional loading case which may be considered as the main cause of the failure. Visual outputs from the simulation results revealed a better understanding of the failure zone on the shaft. The maximum equivalent stress magnitude obtained from the simulation was 632.08 [MPa] (which was lower than the fracture point) on the shaft under maximum PTO torque, however, it was concluded that the main reason for the failure was excessive shock torsional loading. This work contributes to further research into usage of numerical method based deformation simulation studies for the transmission elements used in agricultural tractors/machinery.

There are many factors that influence the health and productivity of the animals in livestock production fields, including temperature, humidity, carbon dioxide (CO2), ammonia (NH3), hydrogen sulfide (H2S), physical activity and particulate matter. High NH3 concentrations reduce feed consumption and cause daily weight gain. In addition, at high concentrations, H2S causes respiratory problems and CO2, displace oxygen, which can cause suffocation or asphyxiation. Good air quality in livestock facilities can have an impact on the health and well-being of animals and humans. Air quality assessment is basically depend on strictly given limits without taking into account specific local conditions between harmful gases and other meteorological factors. The stated limitations may be eliminated using controlling systems based on neural networks and fuzzy logic. This paper describes a fuzzy logic based ventilation algorithm, which can calculate different fan speeds under pre-defined boundary conditions, for removing harmful gases from the production environment. In the paper, a novel model has been developed based on a Mamedani’s fuzzy logic method. The model has been built on MATLAB software. As the result, optimum fan speeds under pre-defined boundary conditions have been presented.

This paper focuses on a case study which can represent a unique application sample for a reverse engineering aided time-dependant non-linear human mastication simulation of agricultural products and its rapid prototyping evaluation. Experimental and theoretical methods and rapid prototyping technology (as an evaluation tool) have been utilised in the case study. A human oral mastication scenario for Pecan kernel has been modelled and simulated respectively through reverse engineered solid models aided explicit dynamics simulation approaches. Subsequently, physical model of the deformation print-out has been produced through rapid prototyping technology. The main aim of the study is to evaluate, understand and demonstrate the deformation dynamics of an agricultural product in human mastication through advanced engineering technologies such as computer aided design, reverse engineering, engineering simulation and rapid prototyping which should be considered as today’s mainstream engineering applications in dentistry/dental, food and agricultural machinery industry, to describe physical deformation dynamics of the agricultural/food products in human consumption and/or machinery design cycle as an important information/knowledge creator for well-designed post-harvest product processing, customer satisfaction, health and medical application perspectives. Visual print-outs from simulation results revealed the deformation dynamics of the kernel under defined boundary conditions. In addition to useful simulation virtual print-outs of the mastication case, time-dependant deformation behaviour of the kernel during mastication were represented through charts. Physically produced deformation case has also provided a good understanding and powerful evaluation ability of the defined mastication scenario.

There are many factors that influence the health and productivity of the animals in livestock production fields, including temperature, humidity, carbon dioxide (CO2), ammonia (NH3), hydrogen sulfide (H2S), physical activity and particulate matter. High NH3 concentrations reduce feed consumption and cause daily weight gain. At high concentrations, H2S causes respiratory problems and CO2, displace oxygen, which can cause suffocation or asphyxiation. Good air quality in livestock facilities can have an impact on the health and well-being of animals and humans. Air quality assessment is basically depend on strictly given limits without taking into account specific local conditions between harmful gases and other meteorological factors. The stated limitations may be eliminated. using controlling systems based on neural networks and fuzzy logic. This paper describes a fuzzy logic based ventilation algorithm, which can calculate different fan speeds under pre-defined boundary conditions, for removing harmful gases from the production environment. In the paper, a novel fuzzy logic model has been developed based on a Mamedani’s fuzzy method. The model has been built on MATLAB software. As the result, optimum fan speeds under pre-defined boundary conditions have been presented.

This paper introduces an advanced engineering simulation procedure for the nonlinear finite element method (FEM) based high-speed shattering case of shelled edible agricultural products. A high-speed impactor which is targeted at the Pecan fruit (kernel-in-shell) was considered in this case study. Physical compression tests were conducted on Pecan fruit specimens and experimental deformation characteristics were utilized to describe realistic material models in the FEM based engineering simulation. Subsequently, a reverse engineering approach was employed in the solid modeling stage and the Pecan shell shattering case under high-speed loading was simulated, considering the explicit dynamics approach. The effect of the high loading rate on the deformation characteristics of the Pecan fruit components was observed. Visual outputs from the simulation revealed the shattering behavior of the Pecan fruit components under defined boundary conditions. In addition to useful visual simulation outputs, time-dependant stress distributions on the Pecan fruit under high-speed loading rates were represented using graphs. Simulation results have revealed that maximum equivalent stress values were 7.1 (MPa), 5.1 (MPa), and 0.336 (MPa) for shell, packing material, and kernel, respectively. Maximum reaction force at impact was calculated as 996,000 (N). This work contributes to further research into the use of nonlinear numerical method based high-speed deformation simulation studies for shelled edible agricultural products.

The characteristics related to the physical properties of agricultural products can be considered when designing and sizing machinery systems/equipment used in agricultural production. Agricultural products as biological/organic materials have several unique characteristics, which set them apart from conventional engineering materials such as steel and plastic based materials, in the context of inner structure and product geometry/shape. Agricultural materials have heterogeneous inner structures and irregular shapes cultured by nature. Most especially, the irregular shape of most agricultural products complicates their physical and engineering analysis. Therefore, precise description of the irregular product geometry/shape is significant for any related analyses used in both product quality evaluation and design of agricultural machinery systems. This study describes a reverse engineering application procedure for precise description of the physical attributes related to geometric features (size, shape, volume etc.) of the agricultural products under consideration. In the study, a three-dimensional (3D) laser scanner has been utilised and 3D digital model data of the selected sample agricultural product (Pecan) processed in the virtual environment through 3D scanner software and 3D parametric solid modelling design software has been collected. After 3D solid models were created, some of the physical attributes related to geometric features of the agricultural products were measured precisely and realistic virtual 3D computer aided design (CAD) data was provided for deeper rheological investigation such as structural deformation, fluid dynamics (flow) and heat transfer analyses of the products by means of computer aided engineering (CAE) techniques. Finally, a comparative deformation simulation case study was concluded. This study contributes to further research into the development of agricultural machinery and equipment through the utilisation of reverse engineerin

This paper introduces an advanced engineering simulation procedure for the nonlinear finite element method (FEM) based high-speed shattering case of shelled edible agricultural products. A high-speed impactor which is targeted at the Pecan fruit (kernel-in-shell) was considered in this case study. Physical compression tests were conducted on Pecan fruit specimens and experimental deformation characteristics were utilized to describe realistic material models in the FEM based engineering simulation. Subsequently, a reverse engineering approach was employed in the solid modeling stage and the Pecan shell shattering case under high-speed loading was simulated, considering the explicit dynamics approach. The effect of the high loading rate on the deformation characteristics of the Pecan fruit components was observed. Visual outputs from the simulation revealed the shattering behavior of the Pecan fruit components under defined boundary conditions. In addition to useful visual simulation outputs, time-dependant stress distributions on the Pecan fruit under high-speed loading rates were represented using graphs. Simulation results have revealed that maximum equivalent stress values were 7.1 (MPa), 5.1 (MPa), and 0.336 (MPa) for shell, packing material, and kernel, respectively. Maximum reaction force at impact was calculated as 996,000 (N). This work contributes to further research into the use of nonlinear numerical method based high-speed deformation simulation studies for shelled edible agricultural products.