Applied Mechanics and Materials Vol. 729

Abstract: The paper presents the results of experimental studies of physical and mechanical properties of casting cores (-set process using Carbectis binder) high-speed heated with subsequent destruction. Based on experimental data, such parameters of deformation model of a core are obtained which permit to calculate the values of hindered shrinkage of AK7Ch alloy with the accuracy of 1.5 %.

Abstract: The article considers the problem of cracks formation in cast-iron molds during the casting of zinc blocks. The analysis of casting technology for manufacturing of cast-iron molds is performed. Changes of the construction of cast-iron molds is implemented to ensure the directional solidification. The analysis of thermal cycles of cast-iron molds during its operation is performed. It is established that the most dangerous moment of crack formation is the beginning of the pouring of molten zinc in the cold cast-iron mold. The new composition of the separation insulating coating, which reduces thermal shock and the probability of crack formation is developed.

Abstract: Thermal kinetic parameters are very often used in the engineering practice for the simplified design of the heat exchangers. These thermal kinetic parameters must be determined from the experimental measurement. This contribution is aimed on the calculation of thermal kinetic parameters from the experimental measurements of heat exchanger water steam / hot water. In this case study are tested and compared tubes with the smooth and structured surface. Obtained results can be directly used in the engineering practice.

Abstract: Application of a very wide range of engineering and construction of concrete beam, generally by the concrete and steel components, plays an important role in civil engineering. The unit adopts the structure of what will maximize the load, is the key problem in the design of concrete beam. This paper analyzes the structural characteristics of the Steel Reinforced Concrete and the bearing capacity, the design of a new type of structure. Application of ANSYS software to carry on the numerical simulation to it, and the concrete materials with different strength grades were bearing contrast; through continuous optimization of steel and concrete structure, complete the optimal combination between material, find Steel Reinforced Concrete structure best, and eventually realize the reasonable design of concrete beam.

Abstract: The topic of this paper is the short review of current state-of-the-art in the field of material models of concrete and its utilization for numerical analysis of concrete and prestressed concrete structures. The problem of compiling constitutive relations for numerical simulation of concrete structures is not yet closed. It is caused by different behavior of concrete in tension and compression. Due to formation and development of cracks it is necessary to describe material model of concrete in tension as precisely as possible. The paper aims to create a brief historical overview in this field and then aims to create a short summary of current approaches that were published in conference contributions and in journals during recent years.

Abstract: Four types of exhaust valve models are established, the lightweight on engine exhaust valve is designed. The results on thermal mechanical coupled analysis of four exhaust valve models show that: The maximum values of mises stress appear in contact surface between the valve cone and valve seat; Comparing the maximum mises stress, as wall thickness of the hollow valve increases, there are gradual decrease trends in the same positions of the valve cone, the locking groove, neck and end face of the valve disc. The research on the stress distribution of exhaust valves and the variation law between hollow valves′s strength and their wall thickness provide a good reference for improvement in the future.

Abstract: Lateral extrusion, sometimes called injection upsetting, offers a product with central boss section having complete or segmented protrusions. Collar flanges, spur gear forms, spline or taper with shaft are examples of the products of produce by lateral extrusion. The aim of this study is to investigate the lateral extrusion of gear-like spline form in terms of forming load and load die filling ratio and comparison the results with those results obtained from a commercially FEM based programme named DEFORM-3D. A series of experiment has been carried out using solid lead billets with two different billet diameters and two different billet heights. Experiments were carried out by using a hydraulic press of which capacity 150 metric tons. Load-stroke relations and die filling ratios are obtained both theoretically and experimentally. It is obviously shown that the results obtained from the DEFORM-3D could be used for simulating of the deformation process.

Abstract: Lateral extrusion, which requires less forming load comparing the closed-die forging, has been presenting a gradually increasing field of application as a type of metal forming wherein advantageous of forging and extrusion are combined. In this study production of a work piece with a single tapered tooth manufactured by the lateral extrusion method has been made and experimental load and die fullness rates have been measured. After that the data obtained from experiments was submitted to the developed artificial neural networks (ANN) model. The ANN model was trained by taking diameter, height and stroke as the input variables and the injection upsetting load as the output parameter. The ANN predicted results were found to be in terms of prediction accuracy with experimental results.

Abstract: The energy balance of Hydraulic Confined Piston Engine (HCPE) is the key to understanding its working mechanism, improving its efficiency. The working principle of HCPE was presented, and the energy balance for the rated condition and application characteristics for the full conditions were also studied. Taking the low thermal value of fuel into account, the percentage of energy loss related to combustion is 54.99%, the percentage related to friction is 5.59%, the hydraulic loss is 1.92% and the other losses are 1.10%; the efficient work is 36.40%. The efficient work and the loss related to combustion are similar to those of a hydraulic free piston engine and medial speed diesel engine.

Abstract: For overcoming flaws of traditional gas stove and kitchen ventilator, the structure and principle of internal combustion stove was put forward, and the prototype was developed and tested. When the opening of gas valve increases, firstly, the thermal efficiency decreases sharply, then smoothly, and thermal efficiency reaches up to 70.93% versus 25% opening of gas valve. The internal combustion stove is very suitable for frying or heating food directly, environmental, energy-saving, safe, compact, etc.