Optimization of isolated and combined pad foundation using computer aided application of finite element approach

Most Finite Element packages provide means to generate meshes automatically. However, the user is usually confronted with the problem of not knowing whether the mesh generated is appropriate for the problem at hand. Since the accuracy of the Finite Element results is mesh dependent, mesh selection forms a very important step in the analysis of isolated and combined footing pad foundation. SAFE is an ultimate tools use in the design of concrete floors and foundation system, hence provide a suitable means for the user. From framing layout all the way through to detail drawing production, SAFE integrate every aspect of engineering design which are in one process easy and intuitive environment. SAFE provides unmatched benefits to the engineer with its truly unique combination of power, comprehensive capabilities, and ease-of-use. In the context of this research, we have plotted graphs showing the relationship between the nodes and displacement with the stress patterns as generated from the software. It is understood from the graph that multiple elements in the process of meshing will make the footing to be at equilibrium. The research also carry the shape deformed diagram which shows the deformation of the footing due to the impose load (stress) on the footing, it also give the bending moment diagram of the footings. The basic structure and analysis of the single and double pad footing foundations have been designed using Finite Element Analysis (FEA) with the failure planes being considered. The results obtained, it is assumed that FEA is an ideal design method that breaks foundation design into basic elements and nodes that shows the action of the loading on the footings.

Mesh Selection for Progressive Failure Modeling of Carbon Fiber Panels in Mode III Shear Using an Explicit Finite Element Solver

Modeling progressive failure of composite materials can be a challenging task. It is further complicated by mesh dependency of finite element solvers when implementing the Hashin criterion. As one continues to refine the mesh, the finite element analysis (FEA) continues to yield varying solutions; hence there is no converged solution for continuous mesh refinement. This is due to mesh dependency when modeling strain softening. The FEA package Abaqus attempts to mitigate this but the issue is not eliminated. Methods that address mesh dependency include experimental validation and numerical analysis. Experimental validation tailors the mesh to match a specific result. This mesh would then be applicable to other configurations with the same geometry and loading; however, experimental validation with increasingly complex parts for FEA is costly and time consuming. Numerical approaches to mesh selection do not require experimental validation; however, these methods may be computationally expensive depending on the analysis. A mesh selection strategy that does not require experimental validation, while computationally efficient, should be implemented for design purposes. This study investigates a mesh selection strategy based on a converged elastic solution; the coarsest mesh that converges to a solution in the linear-elastic portion of the material response is chosen for analysis. Previous studies using an implicit solver yielded good results for out-of-plane loading conditions; however this procedure has not been implemented for explicit solvers. In this study, an investigation was conducted to determine the appropriate mesh to model progressive damage for notched, carbon fiber composite panels in out-of-plane shear (mode III) using an explicit solver in Abaqus/Explicit. This study analyzed 20 ply thick panels and considered three stacking sequences: 10%, 30%, and 50% zero degree plies. The procedure initially disabled damage and identified the coarsest mesh that approached a converged elastic solution. Using this mesh, damage was enabled and the models were run with loading proceeding through damage initiation until failure. The panels’ material response were extracted from the finite element (FE) model and filtered in order to determine their maximum load-carrying ability. The FE predicted maximum loads were then compared to corresponding experimental data in order to validate the mesh selection procedure. This process is not limited to out-of-plane shear; the potential for this mesh selection method would allow for progressive failure simulation to be more applicable in the design process of composite structures instead of post-damage analysis.

Biology, Conservation and Management of Nematopalaemon tenuipes (Aramang) Fishery

Nematopalaemon tenuipes (Aramang) forms almost 100 % of catch by drift filter nets in the Cagayan River Estuary. It is caught throughout the year. The fishery shows varied annual fluctuations for the last five years with an averageannual production of 3,314.596 metric tonnes; the resource does not appearto be under threat of over fishing at present due to increasing production ofcatch from 1996 to 2013. The maturity, fecundity and GSI of aramang weredetermined from collected samples from the gatherers during the observanceof management intervention known as Gentlemen’s Agreement (May 2012 toMarch 2013). Five maturity stages of non-berried and berried aramang occurredthroughout the observation period where nearly ripe and ripe seemed to bedominant comprising more than 70 % in occurrence. The size at maturity wasfound to be 45 mm in total length with an estimated mean fecundity of 974.92eggs. Pearson correlation showed a significant relationship between fecundityand size at (p < 0.01). However, no significant correlation (p > 0.01) was foundbetween GSI and size. The seasonal variation in the GSI showed continuousspawning of N. tenuipes throughout the year. Using mesh size 1.60 cm wasefficient to exclude small size of aramang in the catch, thereby attaining an idealcatch size resulting in better price and higher profit.Keywords: Reproductive Condition, Growth and Recruitment, Mesh selection,Nematopalaemon tenuipes, Aparri, Cagayan