Structural integrity of precast panel shear walls

1982 ◽  
Vol 9 (1) ◽  
pp. 13-24 ◽  
Author(s):  
O. A. Pekau

Precast panel shear walls are investigated for conditions simulating progressive collapse. The latter are simulated by assuming ineffective panels at various levels within the structure. The analysis is performed by an efficient finite element substructuring procedure for both static and seismic loadings, and by a simple rigid-cantilever approximation for static loading only. The principal interest concerns the magnitude and distribution of design forces in vertical and transverse ties which, in the finite element analysis, are modelled by discrete connectors along horizontal and vertical joints. For static loading the results evaluate the accuracy of the simple cantilever design procedure, whereas for seismic loading the magnitude and distribution of connector forces resulting from local panel failure are examined. In particular, it is shown that failure of an exterior panel leads to unexpectedly large concentrations of shear force in the vertical joint, something that is not adequately predicted by the simplified cantilever analysis.

2020 ◽  
Vol 8 (6) ◽  
pp. 4354-4357

This research seeks to develop a comprehensive framework for the design of Half-Tunnel Concrete Formwork System (HTCFS). HTCFS are highly efficient systems that are used for the construction of modular RCC structural systems. Additionally, HTCFS are significant in terms of higher reuse in constructing modular units. Despite these advantages, the actual design procedure adapted for HTCFS was not well elucidated so far, many companies adapt their own design methodology and hence it is highly important to develop a simplified straight forward design methodology incorporating all comprehensive associated factors. Initially, the detail introspective assessment of various types of HTCFS are perceived. Then using this information, a 3D Solid model is developed, and eventually, the 3D model gets converted into 3D solid CAE model using sophisticated Finite Element package for the Finite Element Analysis (FEA). This procedure is repeated for different combinations of components that construed effective systematized HTCFS. From the FEA the optimal structural components required for the structural integrity of HTCFS are established.


2011 ◽  
Vol 39 (4) ◽  
pp. 223-244 ◽  
Author(s):  
Y. Nakajima

Abstract The tire technology related with the computational mechanics is reviewed from the standpoint of yesterday, today, and tomorrow. Yesterday: A finite element method was developed in the 1950s as a tool of computational mechanics. In the tire manufacturers, finite element analysis (FEA) was started applying to a tire analysis in the beginning of 1970s and this was much earlier than the vehicle industry, electric industry, and others. The main reason was that construction and configurations of a tire were so complicated that analytical approach could not solve many problems related with tire mechanics. Since commercial software was not so popular in 1970s, in-house axisymmetric codes were developed for three kinds of application such as stress/strain, heat conduction, and modal analysis. Since FEA could make the stress/strain visible in a tire, the application area was mainly tire durability. Today: combining FEA with optimization techniques, the tire design procedure is drastically changed in side wall shape, tire crown shape, pitch variation, tire pattern, etc. So the computational mechanics becomes an indispensable tool for tire industry. Furthermore, an insight to improve tire performance is obtained from the optimized solution and the new technologies were created from the insight. Then, FEA is applied to various areas such as hydroplaning and snow traction based on the formulation of fluid–tire interaction. Since the computational mechanics enables us to see what we could not see, new tire patterns were developed by seeing the streamline in tire contact area and shear stress in snow in traction.Tomorrow: The computational mechanics will be applied in multidisciplinary areas and nano-scale areas to create new technologies. The environmental subjects will be more important such as rolling resistance, noise and wear.


1998 ◽  
Vol 26 (1) ◽  
pp. 51-62
Author(s):  
A. L. A. Costa ◽  
M. Natalini ◽  
M. F. Inglese ◽  
O. A. M. Xavier

Abstract Because the structural integrity of brake systems and tires can be related to the temperature, this work proposes a transient heat transfer finite element analysis (FEA) model to study the overheating in drum brake systems used in trucks and urban buses. To understand the mechanics of overheating, some constructive variants have been modeled regarding the assemblage: brake, rims, and tires. The model simultaneously studies the thermal energy generated by brakes and tires and how the heat is transferred and dissipated by conduction, convection, and radiation. The simulated FEA data and the experimental temperature profiles measured with thermocouples have been compared giving good correlation.


2015 ◽  
Vol 12 (19) ◽  
pp. 5871-5883 ◽  
Author(s):  
L. A. Melbourne ◽  
J. Griffin ◽  
D. N. Schmidt ◽  
E. J. Rayfield

Abstract. Coralline algae are important habitat formers found on all rocky shores. While the impact of future ocean acidification on the physiological performance of the species has been well studied, little research has focused on potential changes in structural integrity in response to climate change. A previous study using 2-D Finite Element Analysis (FEA) suggested increased vulnerability to fracture (by wave action or boring) in algae grown under high CO2 conditions. To assess how realistically 2-D simplified models represent structural performance, a series of increasingly biologically accurate 3-D FE models that represent different aspects of coralline algal growth were developed. Simplified geometric 3-D models of the genus Lithothamnion were compared to models created from computed tomography (CT) scan data of the same genus. The biologically accurate model and the simplified geometric model representing individual cells had similar average stresses and stress distributions, emphasising the importance of the cell walls in dissipating the stress throughout the structure. In contrast models without the accurate representation of the cell geometry resulted in larger stress and strain results. Our more complex 3-D model reiterated the potential of climate change to diminish the structural integrity of the organism. This suggests that under future environmental conditions the weakening of the coralline algal skeleton along with increased external pressures (wave and bioerosion) may negatively influence the ability for coralline algae to maintain a habitat able to sustain high levels of biodiversity.


Author(s):  
N. Shimizu ◽  
H. Nasuno ◽  
T. Yazaki ◽  
K. Sunakoda

This paper describes a methodology of design and analysis of viscoelastic seismic dampers by means of the time domain finite element analysis. The viscoelastic constitutive relation of material incorporating with the fractional calculus has been derived and the finite element formulation based on the constitutive relation has been developed to analyze the dynamic property of seismic damper. A time domain computer program was developed by using the formulation. Dynamic properties of hysteresis loop, damping capacity, equivalent viscous damping coefficient, and equivalent spring constant are calculated and compared with the experimental results. Remarkable correlation between the FE analysis and the experiment is gained, and consequently the design procedure with the help of the FE analysis has been established.


2021 ◽  
Vol 335 ◽  
pp. 03011
Author(s):  
Mohammed Shariff Mohamed Sulaiman ◽  
Seong Chun Koay ◽  
Ming Yeng Chan ◽  
Hui Leng Choo ◽  
Ming Meng Pang ◽  
...  

This research investigated the lattice structure fabricated using corn husk fibre reinforced recycled polystyrene composite using Finite Element Analysis (FEA). The material’s properties of this composite material were obtained from previous study. Then, the lattice structure of lattice structure was created using Creo® software and the FEA simulation was done by ANSYS software. In this study, the lattice structures were created using triangular prism and hexagonal prism. The analysis was divided into two conditions: 1) lattice structure with different prism shape and similar surface area, 2) lattice structure with varies of strut thickness and 3) lattice structure with different prism shape and similar lattice parameter. The results show the lattice structure with triangular prism have more structural integrity than hexagonal prism. Then, lattice structure with triangular prism can be built with lesser material but stronger and stiffer than lattice structure with hexagonal prism.


2007 ◽  
Vol 353-358 ◽  
pp. 2855-2859
Author(s):  
W.C. Lee ◽  
Chae Sil Kim ◽  
J.B. Na ◽  
D.H. Lee ◽  
S.Y. Cho ◽  
...  

Since most marine engines are generally very huge and heavy, it is required to keep safety from accidents in dealing them. Several types of lifting lugs have been used to assemble hundred ton–large steel structures and carry the assembled engines. Recently a few crashes have been occurred in carrying engines due to breaking down the lugs. Although the stability evaluation of the lifting lug has therefore been very important for safety, systematic design procedure of the lugs, which includes the structural analysis considering stability, has few reported. This paper describes the three dimensional finite element structural modeling for a lifting lug, the studies for determining the reasonable loading and boundary conditions, and the stability evaluation with the results of structural analyses. It should be very helpful for designing the other types of lifting lugs with safety.


Author(s):  
P. Y. Shim ◽  
S. Mannoochehri

Abstract This paper presents a hybrid shape optimal design methodology using an implicit differentiation approach for sensitivity analysis and a node removal technique for shape alteration. The approach presented attempts to overcome the weaknesses inherent in each individual technique. The basic idea is to combine the sensitivity analysis, which forms the analytical basis for the algorithm, and a node removal technique, which grossly modifies the shape without the need for a remeshing after each iteration. The sensitivity analysis is based on the finite element equilibrium equation and the implicit differentiation technique. It examines the effect positional changes of the boundary nodes have on the stress values. Using the sensitivity results, a sequential linear programming algorithm is utilized to determine optimum positions of the boundary nodes. These optimization results are provided as inputs to an algorithm that decides which boundary nodes should be removed. By removing boundary nodes, the boundary elements change to either a triangular or a non-existent type. This shape modification procedure starts from the boundary elements and moves toward the internal elements. Only two iterations of finite element analysis are required to modify one boundary layer. To maintain the structural integrity and the connectivity of the elements in the model, a connectivity check is performed after each iteration. Three design examples are given to illustrate the accuracy and the steps involved in the proposed optimal design methodology.


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