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Large-format additive manufacturing is a candidate for tremendous savings in terms of time and cost while simultaneously enabling higher flexibility, quality, and variability. Most of the design constraints of small-scale polymer 3D printers still apply to large-format additive manufacturing. The paper details both the strengths and deformation-related design considerations for additive manufacturing to gain a better understanding of the material capabilities and limitations, mechanical characteristics, and how to use them for large-format additive manufacturing (LFAM). The results show that the tested materials for additive manufacturing meet the requirements from the stress and deformation points of view. Compared to the steel and composite material, the strength limits are lower, but high enough for the given load. The materials HI TEMP, HI TEMP CF, PA12CF, PA6/66, and PLA seem to be the most promising for LFAM to create a firefighting water tank. The results may be considered as an introduction to further research that should lead to real solutions for the production of atypical tanks. [ABSTRACT FROM AUTHOR]

The article examines deformation of wood veneer and internal forces resulting from bending. Wood is modelled as an orthotropic material. A thin circular wooden plate hemispherically supported at its free edge is bent by axial hubbing of the punch with a hemispherical end. The analysis of the models is carried out by the ANSYS software. Geometric boundary conditions are calculated and set by a macro formed by the APDL (ANSYS Parametric Design Language) scenario language. For the reason of comparison the models were solved for a given plate with simplified boundary conditions. [ABSTRACT FROM AUTHOR]

Laminar free convection heat transfer from a heated cylinder and tube arrays is studied numerically to obtain the local and average Nusselt numbers. To verify the numerical simulations, the Nusselt numbers for a single cylinder were compared to other authors for the Rayleigh numbers of 103 and 104. Furthermore, the vertically arranged heated tube arrays 4 × 1 and 4 × 2 with the tube ratio spacing SV/D = 2 were considered, and obtained average Nusselt numbers were compared to the existing correlating equations. A good agreement of the average Nusselt numbers for the single cylinder and the bottom tube of the 4 × 1 tube array is proved. On the other hand, the bottom tubes of the 4 × 2 tube array affect each other, and the Nusselt numbers have a different course compared to the single cylinder. The temperature fields for the tube array 4 × 4 in basic, concave, and convex configurations are studied, and new correlating equations were determined. The simulations were done for the Rayleigh numbers in the range of 1.3 × 104 to 3.7 × 104 with a tube ratio spacing S/D of 2, 2.5, and 3. On the basis of the results, the average Nusselt numbers increase with the Rayleigh numbers and tube spacing increasing. The average Nusselt number and total heat flux density for the convex configuration increase compared to the base one; on the other hand, the average Nusselt number decreases for the concave one. The results are applicable to the tube heaters constructional design in order to heat the ambient air effectively. [ABSTRACT FROM AUTHOR]