Zdenek Chval

DESIGN OF MECHANICAL FORGING PRESS WITH MAXIMAL FORCE IN SIDE CAVITY

This paper deals with design of crankshaft forging press for multi-cavity forging with maximal forging force in on of side cavities. As a tool was used optimization of structure, structural FEM analysis and geometrical modification of frame. Results are in more uniform stress distribution in whole structure of forging press. This design leads to optimized production and improved quality of final products. Forging press with this modification has higher durability and it has competitive advantage.

Dimension Stability of Thin-Walled Parts from 3D Printed Composite Materials

3D print of composite materials is one of the rapidly developing areas of additive manufacturing technology. This technology is using (instead of advanced FDM or SLA technologies) materials reinforced by short or micro fibres (mainly carbon or glass fibres). These fibres are oriented mainly in direction of filament extrusion. This is causing transverse- isotropic mechanical properties of final part. Composite materials with short fibres has higher modulus of elasticity, higher strength in bending, better thermal stability and higher impact resistance. These properties can be defined by change of volume rate between matrix and reinforcement. It is noticed nowadays, that these materials are more used in automotive and aerospace industry.

Influences of pressures and cycle times on properties of final plastic product from HDPE

This paper deals with the possibilities of improving the quality of final product from plastic material. Advanced CAE simulation with finite element method was used as a tool for this research. Main aim of this article is to show procedure how to determine optimal level of injection pressure, packing pressure and times of all injection phases. All these parameters lead to improving of final properties of product. Wide range of values is given for each parameter and it is necessary to determine the suitable value. Exact influences of each parameter on the final product were detected with usage of CAE simulations of injection molding. All these dependencies were in article described. Research was focused on influence of all parameters on final product and also on technological process. Level of mold filling, number and size of weld lines, number of air traps and overall production times were chosen as main parameters for evaluation. Reference part is reinforcement profile from spoiler in racing formula car. Process with mean values of each parameter was chosen as a reference process. Influence were tested on product from high density polyethylene. Material properties for CAE simulation were clearly described in this article. All simulations were validated by experiment performed on real injection molding machine.