Utilization of fused deposition method 3D printing for evaluation of discrete element method simulations

FDM 3D printing is used for designing prototype assessment in engineering production. It is usually used to verify the functionality of kinematics mechanisms. It can also be used for innovation in agricultural production, eg. the development of new mechanisms for agriculture tools. Such a mechanism as well as the entire components is printed using FDM and they are made of plastics. This whole can be experimentally verified in a laboratory trough. The article deals with the verification of the possibilities of using FDM technology for the design of agricultural tools. The material properties, namely stress-strain, of the plastics after printing are entered into the Ansys mechanical library, and the DEM results are also imported into Ansys mechanical. Material properties of plastics for FDM technology such as PLA, PETG show that its mechanical properties limited their using for validation

Discrete element simulation of rapeseed shear test

ArticleSuiTable equipment are required for storage and transportation of rapeseed which are developed according to rules for bulk matters. It is one of reasons where bulk matter properties are important to the design. Bulk matter properties are important to known as angle of repose, internal friction, external friction, adhesivity force and other bulk properties. Experimental values of bulk properties are added to mathematical models. The model should be calibrated with adequate experiment. The shear test is one of popular calibration test for bulk matters so that be able done experiment and numerical model in one. The aim of this paper is simulation of rapeseed bulk properties during shear strain and flow and its evaluation and calibration with experimental tests. RockyDEM software was used for numerical simulation of rapeseed. Shear test, angle of repose, static and dynamic friction test were used to calibration of the numerical rapeseed model. Sensitivity of numerical model is discussed on the bulk properties

DEM modelling of tillage tools in sand and verification of draft forces in the soil box

Received: April 28th, 2021 ; Accepted: September 29th, 2021 ; Published: October 25th, 2021 ; Correspondence: [email protected] resistance is still being important parameter during tillage. By reducing the soil resistance during processing, greater efficiency and cost reduction can be achieved. With the correct design of the shape of the tillage tools, reduction in the force required for tillage can be achieved. New tool designs must be tested in field conditions to determine the effect. Using DEM (Discrete element method) modelling, individual designs can be compared without the need for field tests. However, the accuracy of the model must first be verified on real tests. The paper deals with the creation of a mathematical model of sand, which is used for testing tillage tools in the soil box. The models are focused on tests of various shapes of wings on tillage tools. Draft forces are compared, and the correctness of the model is verified

Tracing of the rapeseed movement by using the contrast point tracking method for DEM model verification

Received: May 30th, 2022 ; Accepted: August 1st, 2022 ; Published: August 4th, 2022 ; Correspondence: [email protected] designing the efficient storage and transport of rapeseed, it is necessary to follow the rules of bulk material, know its properties, and use appropriate equipment. The mentioned properties of bulk material are essential for simulating the numerical model and obtaining the parameters of the geometry particle tracing during the rapeseed manipulation. In order to determine the angle of repose and mechanical properties of rapeseed, the results of previous experiments were used. The aim of this paper was to propose the methodology for calculating the traces of individual particles using the contrast point method during a real test to calibrate and verify a numerical model of the same system as in a real test. RockyDEM software was used to create the numerical model of rapeseed. The numerical model was used to test the flow analysis of rapeseed particles. The experiment measuring rapeseed particle traces was performed using an assembled experimental device. The rapeseed particles and the contrast point particles were poured out from the device, and a camera recorded the process. In parallel with the real experiment, the angle of repose test was performed on the same device to verify the numerical model. The results showed that the methodology is suitable for the DEM model verification with an accuracy of 3.77 mm in the X-axis, 0.55 mm in the Y-axis and 1.7 mm in the Z-axis. This confirmed that the proposed method is suitable for determining the surface behaviour of bulk material to verify the DEM model

A good death – can the concept be applied to anatomy?

The importance of patient‐centered decisions is embedded throughout clinical practice. The principle that the patient is at the center of all decisions has helped form the contemporary approach to death and dying. The concept of a ‘good death’ will naturally mean different things to different individuals, but is based on the foundation of being pain free, comfortable and able to make informed decisions. Potential donors are faced with many personal, ethical and often spiritual considerations when they come to think about their wishes after death. One consideration is that of a ‘good death’. This article explores how the concept of a ‘good death’ may be applied to anatomy. Where first person consent is in place, the motivating factors frequently include the wish for others to learn from the donation, and this notion may form part of the ‘good death’ for the donor. Such motivations may impact positively on how students feel about dissecting and may provide comfort, assuaging feelings of discomfort and allowing students to focus on anatomical learning. For donors where second person consent is in place, the concept of a ‘good death’ must depend on whether the individual wanted to donate their body in the first instance. The notion of a ‘bad death’ may also be considered with body donation where no consent for donation is in place. This article proposes that there is ultimately a place for the concept that a ‘good death’ may involve an individual donating their body to medical education