Principles of Stress-Strength Modelling of the Highly Thermally Loaded Materials—The Influence of an Effect of Strength Differential on the Material Effort

This paper presents an improvement in the Huber–Mises–Hencky (HMH) material effort hypothesis proposed by Burzyński. Unlike the HMH hypothesis, it differentiates the plastic effort between compression and tensile load states, and links shear with tensile limit. Furthermore, it considers the fact that construction materials do not have infinite resistance in the pure tensile hydrostatic load state, which was proved by the static load experiment performed on St12T heat-resistant steel. The asymmetry between tensile and compressive loads is captured by the elastic region asymmetry coefficient ϰ, which was established by experiment for St12T steel in the temperature range between 20 °C and 800 °C.

Numerical Simulation of Static Seal Contact Mechanics Including Hydrostatic Load at the Contacting Interface

A finite element model of a static seal assembled in its housing has been built and is utilized to study how the seal deforms under varying loading conditions. The total contact load on the sealing surface is balanced by the sealed fluid pressure and the friction between the seal and the housing sidewall perpendicular to the sealing surface. The effect of the sealed fluid pressure between the sealing surfaces was investigated and the simulation showed that the surface profile is distorted due to the hydrostatic pressure. We study the distorted contact profile with varying sealed fluid pressure and propose five parameters to describe the corresponding contact pressure profile. One of these parameters, overshoot pressure, a measure of the difference between maximum contact pressure and the sealed fluid pressure, is an indicator of sealing performance. The simulations performed show different behaviors of the overshoot pressure with sealed fluid pressure for cosinusoidal and parabolic surfaces with the same peak to valley (PV) value.

Numerical Analysis of the Bottom Thickness of Closed Rectangular Tanks Used as Pontoons

This paper concerns the numerical analysis of closed rectangular tanks made in one stage, used as pontoons. Such structures can be successfully used as floating platforms, although they primarily serve as floats for ‘houses on water’. Amphibious construction has fascinated designers for many years and is becoming, in addition to a great and prestigious location for many purposes, a practical global necessity. Severe weather phenomena that no country is safe from, i.e., heavy rains or floods, combined with the scarcity of space intended for the construction of residential buildings, encourage development at the contact of water and land or on water only. This paper contains an analysis of the static work of tanks with different bottom thickness subjected to hydrostatic load acting on tank walls and the bottom plate and evenly distributed load acting on the upper plate, i.e., major impacts that occur when tanks are used as pontoons. Calculations were made using the finite difference method in terms of energy, assuming the Poisson’s ratio ν = 0. Based on the solutions obtained, charts were made that illustrated the change in bending moments at the characteristic points of the analysed tanks depending on acting loads. The article also includes calculations of buoyancy, stability and the metacentric height for tanks with different bottom thicknesses, with the main purpose being to improve and share knowledge on their safe use as pontoons.

Design and Analysis of Lightweight Fire Extinguishers using Alternately Available Metals

This research aims to optimize the weight of already existing fire extinguishers containing Carbon Dioxide as per BIS standards IS 2190: 2010 and IS 7285-1: 2004. In the paper, an optimized and new design is proposed to minimize the weight of the pressure vessel making it easier to store in smaller compartments and also allowing faster hand-held use during an emergency. The weight has been reduced substantially by using proposed materials and FEA simulations were performed on the model to check for failures under the set test conditions with the aim to minimize the volume of metal used that is able to withstand the hydrostatic load of pressure gas. ANSYS Mechanical 18.2 was used for performing 3d pressure analysis while the model was designed on Solidworks 2016. A Multi Frontal Direct Solver was preferred to reach the solutions in every case. The analysis results of all the materials were compared and finally, a material was selected that was tough enough to clear the safety standards and extremely light so that even old people could use it without any issues. A simple shell of Titanium Grade-5 Alloy was found to be the proper and optimal choice to obtain good mechanical properties and lightweight.

Real-Time Monitoring and Detection of Emissions in Vehicles

This research aims to optimize the weight of already existing fire extinguishers containing Carbon Dioxide as per BIS standards IS 2190: 2010 and IS 7285-1: 2004. In the paper, an optimized and new design is proposed to minimize the weight of the pressure vessel making it easier to store in smaller compartments and also allowing faster hand-held use during an emergency. The weight has been reduced substantially by using proposed materials and FEA simulations were performed on the model to check for failures under the set test conditions with the aim to minimize the volume of metal used that is able to withstand the hydrostatic load of pressure gas. ANSYS Mechanical 18.2 was used for performing 3d pressure analysis while the model was designed on Solidworks 2016. A Multi Frontal Direct Solver was preferred to reach the solutions in every case. The analysis results of all the materials were compared and finally, a material was selected that was tough enough to clear the safety standards and extremely light so that even old people could use it without any issues. A simple shell of Titanium Grade-5 Alloy was found to be the proper and optimal choice to obtain good mechanical properties and lightweight.

Role of Solutions when Metasomatic Transformations in Construction Composites

In the framework of development of the transdisciplinary research area «geonics» or «geomimmetics» the term «technogenic matasomatosis in construction material science» was proposed. This work is devoted to study of processes that take place in construction material when buildings management from the point of view of the technogenic metasomatosis theory: adaptation of rocks to varied technogenic conditions. The determination and calculation of coefficient of permeability for fine-aggregate concrete with different density and chemical composition of the filtrate under high-hydrostatic load was accomplished. The method of determination of a mineral basicity using thermodynamic calculation of mineral ionization was applied. It was determined, under these conditions the minerals of calcium and magnium silicates have a higher more basicity and, so, have a higher solubility vs. calcium and magnium carbonates.

The Optimal Design of a Functionally Graded Corrugated Cylindrical Shell under Axisymmetric Loading

Optimization of parameters of the corrugated shell aims to achieve its minimum weight while keeping maximum stiffness ability. How an introduction of functionally graded corrugations resulted in improved efficiency of this thin-walled structure is demonstrated. The corrugations are graded varying their pitch. The effect of variation in pitch is studied. Homogenization approach gives explicit expressions to calculate the equivalent shell properties. Then well-elaborate methods of optimal design theory are used. The illustrative examples for hydrostatic load demonstrate a high efficiency of the used method.