An implicit non-ordinary state-based peridynamics for large deformation solid mechanics problems

The numerical simulation of the cracking process remains one of the most significant challenges in solid mechanics. Compared classical approaches, peridynamics(PD) has some attractive features because the basic equations remain applicable even when singularities appear in the deformation. Numerical time-integration plays a big role in any computational framework and unlike explicit time-integration, implicit time-integration methods can be much more efficient because of the ability to adopt fairly large time increments, making it a suitable option for PD analyses of large deformation problems. The objective of this thesis is to propose an implicit non-ordinary state-based peridynamics (NOSB PD) approach focusing on quasistatic analyses with large deformation mechanics. Firstly, the use of the adaptive dynamic relaxation (ADR) method as a solution strategy for quasi-static analyses with large deformation mechanics is discussed. Next, an analytical expression of the Jacobian matrix based on the equation of motion of NOSB PD is formulated to ensure optimum convergence of the global residual force. To address some instability issues in the existing “corresponding material” model, caused by zero-energy modes instability, recent approaches proposed by Silling (2017) are used to control the spurious deformation modes. An additional stabilisation term with respect to displacement is included in the derivatives for Jacobian formulation. This allows a more accurate NOSB PD approach to model material behaviour where correspondence materials have previously failed due to instability. Finally, to validate the proposed methodology, several numerical examples of 2D damage problems model using a stabilised correspondence model are verified, and suggestions are made for future implementation. The novelty of this thesis lies in providing theoretical development and numerical implementation of an implicit non-linear NOSB PD focusing on quasi-static analyses with large deformation mechanics. Findings from this thesis will interest researchers working in numerical methods, along with those solving discontinuous solid mechanics problems

Finite element analysis of rapid footing for industrialised building system

The design and innovation of Industrialized Building System (IBS) requires lighter, stronger, better shape, and versatility. Therefore IBS has a common definition and perspective that coordinated in precision to form a structure. This paper presents finite element analysis on two different shape of rapid footing in order to obtain it potential to be immersed using forced vibration. The shapes are different in terms of the bearing area that in contact between footing and the soil surface. Test were conducted on granular soils of elastic modulus of 0.0174 N/mm2and structures are vibrated vertically. The result obtained from the laboratory test on sand is compared with the result from finite element analysis for comparison. The vertical settlement of the footing of model 1 from laboratory test is 2 mm while from analysis is 3.40 mm. The vertical settlement of the footing of model 2 from laboratory test is 7mm while from analysis is at 7.02 mm. Results showed that the footing with confinement wall experienced higher settlement than the footing without wall due to its small contact area

Evaluation of Emissions by Different Analysis Method at Hot Mix Asphalt Plant Combustion Source

The combustion process for the asphalt mixing in hot mix asphalt (HMA) plant can produce harmful flue gases emission into the atmosphere. Combustion activities produce heat for industrial usage when fuel reacts with oxygen in the air under suitable conditions. High concentrations of undesirable emissions can be formed if the combustion is not properly controlled during the reaction. This paper gives an overview on the method and measurement of these emissions in combustion analysis by focusing on the three types of analysis methods which are laboratory testing analysis, on-site emission analysis, and theoretical analysis. Three types of data were prepared in order to achieve the objective of the study, which are literature study, site visit, and laboratory analysis. The result shows that there is slightly different emission results even though they came from the same source. Clearly, the analysis shows that the air-fuel ratio during combustion can have a significant effect on the emission result. The excess air supplied can cause dilution to the emission and leads to a low emission value

Evaluation of Emissions by Different Analysis Method at Hot Mix Asphalt Plant Combustion Source

The combustion process for the asphalt mixing in hot mix asphalt (HMA) plant can produce harmful flue gases emission into the atmosphere. Combustion activities produce heat for industrial usage when fuel reacts with oxygen in the air under suitable conditions. High concentrations of undesirable emissions can be formed if the combustion is not properly controlled during the reaction. This paper gives an overview on the method and measurement of these emissions in combustion analysis by focusing on the three types of analysis methods which are laboratory testing analysis, on-site emission analysis, and theoretical analysis. Three types of data were prepared in order to achieve the objective of the study, which are literature study, site visit, and laboratory analysis. The result shows that there is slightly different emission results even though they came from the same source. Clearly, the analysis shows that the air-fuel ratio during combustion can have a significant effect on the emission result. The excess air supplied can cause dilution to the emission and leads to a low emission value