Static Structural Analysis Research Articles

Non linear static analysis of stiffness irregular RC structures

Vertical structures exhibit flexibility than ordinary structures and also they show sensitivity in earthquake excitation. As per the safety standards of construction, structures are built with simple and uniform configurations. Focusing on aesthetic view of these vertical structures, discontinuity in stiffness occurs there by resulting in soft storey. this feature is highly undesirable in buildings especially in seismic active zones. However soft storey cause large deformations at the junction of building lead a greater failure for life and property. An attempt has been made to predict seismic performance of these structures considering G+ 14 storeys. Developing soft storey at base and mid level of G+14 structure and evaluating its seismic performance under non linear static analysis by using SAP2000. A comparative study is made based on, with and without soft storey of G+14 structure and results are tabulated.

Sensitivity study of numerical and geometrical parameters for structural mechanical analyses in the automatic design process of hydraulic machines

In the present paper a sensitivity study of numerical and geometrical parameters related to structural mechanical analyses of a hydraulic machine is presented. The sensitivity study is carried out for the blades of two different hydraulic machines, a propeller blade of a submersible vehicle and a runner blade of a kinetic river turbine. The focus of this work is on static structural mechanical analyses, which are performed with the open source finite element program CalculiX. Parameters for the sensitivity study are numerical parameters like the global mesh size as well as the local mesh refinement at certain locations of the blade. Furthermore, the sensitivity of geometrical parameters such as the blade thickness at different locations or the shape of the fillet is investigated. The results of the sensitivity study show that the numerical parameters have a small influence compared to the geometrical parameters. The most dominant geometrical parameter is the blade thickness at the hub. In case of a high load due to the centrifugal force, the influence of the blade thickness at the tip of the blade increases.

Modal interactions of a dual-joint cylindrical shell system via Nonlinear Normal Modes

Bolted flange joints are commonly encountered in engineering structures. One specific challenge that is regularly encountered is the modeling of connecting interfaces between flanges. Indeed, for large amplitudes of vibration, due to discontinuity of the structure and mechanical contact of the connecting interface, clearances may occur between flanges and cause local stiffness loss, exhibiting complicated nonlinear dynamic behavior. In this paper, a simplified dynamic model for bolted flange joint via structural static analysis is proposed, in which the stiffness nonlinearity due to the non-smoothness of jointed interface is characterized by piecewise-smooth springs. The proposed simplified model has demonstrated good accuracy and precision in capturing the nonlinear dynamic characteristics of bolted flange connections. Following the simplified modeling technique and focusing on the stiffness nonlinearities, an analytical dual-joint system with free–free boundary conditions is established capturing the interaction of a longitudinal mode with two bending modes. The Harmonic Balance Method combined with Asymptotic Numerical Method (HBM–ANM) is utilized to estimate Nonlinear Normal Modes (NNMs) of the system, which provide an interpretation of the underlying nonlinear dynamic behavior, including bifurcation analysis, internal resonances characterization, and stability properties. Especially, internal resonances between the three modes can be triggered at high energy (oscillation amplitude) level, without having commensurate linear natural frequencies, leading to qualitative changes in periodic motions and internal loads environment of the system. The influences of linear frequency ratios and stiffness nonlinearity of each joint on the dynamics of the system are discussed in terms of NNMs. It is interesting to reveal that reducing the stiffness nonlinearity of joint may grow the complexity of the nonlinear dynamics of the system, from the perspective of motion stability, and trigger internal resonance with a complex topology. The studies in this paper provide an in-depth understanding of the nonlinear dynamic behavior of dual-joint systems, and the NNMs certainly represent a useful framework that could lead to a better dynamic design of jointed structures.

Structural Comparison of Naturally Aspirated and Turbocharged Diesel Engine for Steel and Aluminium Made Radiator: A Finite Element Study

The current study is based on the structural analysis of radiators made of different materials to compare their effectiveness in the case of naturally aspirated and turbocharged diesel engines. For the analysis of the radiator structure, ABAQUS software was used. In the ABAQUS, static structural analysis was made to calculate the strength of the radiator. The said software is capable of calculating the strength of the radiator considering the boundary conditions (i.e., fixing at corners) as well as the loading conditions. It was observed that stresses generated while using an aluminium radiator were very high than those produced by steel radiators. According to the study, the following are the key findings for the steel and aluminium radiators. In the first case, while three corners were fixed, the steel radiator showed a deflection of 1.86 mm while aluminium exhibited 5.65 mm. However, in the second case in which the radiator had four fixed corners, the deflection of the steel radiator was 1.10 mm, while that of aluminium was 3.36 mm. Additionally, based on the deflections obtained from all investigations, it was found that radiators made of aluminium were more sensitive than those made of steel in both naturally aspirated and turbocharged applications. However, due to aluminium’s strong thermal conductivity, it is compatible with naturally aspirated engines in terms of thermal capacity. To combat turbocharged engine complications caused by high temperatures, such as thermal cracking, engine wear and tear, and so on, a steel-made radiator is more suitable than an aluminium radiator, hence mitigating the issues.

ANALISA DAN REDESAIN SPROCKET ASSEMBLY CONVEYOR RAKE C2 DI STASIUN KETEL PG NGADIREJO

Abstract. In the Ngadirejo sugar plant, sprocket shaft on the east C2 rake conveyor at the boiler station always failure every year. This conveyor is used for the process of fuel dregs supply at the boiler station. In this research, the analysis of failure and fatigue with the finite element method in Ansys will be carried out. The material analyzed is HQ705 with static loading. The analysis carried out includes static structural analysis and fatigue analysis on the sprocket shaft. Based on this analysis, found that the maximum displacement is 0.001163 m, the maximum equivalent stress is 71.8 MPa, the minimum life is 17.237 cycles, the maximum shear stress is 38.44 MPa, the minimum safety factor is 0.557744. The failure in the FEM analysis results in accordance with the actual failure location. The redesign process was carried out with HQ709 material, with this material the minimum life value is 50539 cycles.

Creep analysis of Water tank made of Polypropylene (PP) and High-Density Polyethylene (HDPE) polymer material using ANSYS Simulation

The present study investigates the creep behavior of water tank manufactured from Polypropylene (PP) and High-Density Polyethylene (HDPE) polymeric material at 40 °C using ANSYS simulation software. Creep fracture is one of the major industrial problems for a product used for a long period of time. The creep analysis using simulation software is one of the ways to predict the life and durability of a plastic product with low cost and may help in optimizing its design. The PP and HDPE manufactured water tanks were commonly used for storing water in household and industrial applications. In this paper, a water tank were designed using an academic 3-Dimensional SOLIDWORKS software and ANSYS WORKBENCH were used for analyzing the creep strain for the developed CAD model. The CAD modelled water tank was tetrahedron meshed and simulated using static structural analysis and varying hydrostatic pressure were applied on the inner walls of the tank. The base of the tank was constrained to fixed. The analytical model based on modified time hardening creep model were implemented to analyze the creep strain. From the simulation, equivalent (Von-Misses) Stress, equivalent creep strain and total deformation were observed for the developed model. The obtained Creep strain-time graph were used to analyze the creep strain of PP and HDPE materials over a long period of time. From the simulation, it is observed that the material PP is more creep resistant than HDPE as equivalent stress of PP is more than HDPE at the applied hydrostatic pressure and the deformation for PP material were less compared to HDPE. The simulated limiting creep strain of PP as well as HDPE was in good agreement with the comparison of maximum limiting creep strain calculated from the material database.

Numerical implementation for isogeometric analysis of thin-walled structures based on a Bézier extraction framework: nligaStruct

We present an open Octave/Matlab package nligaStruct, for linear and nonlinear isogeometric analysis of thin-walled structures. nligaStruct is an extension of NLIGA in aspect of isogeometric structural analysis. A framework for Bézier extraction of T-spline and NURBS is embedded in the simulation pipeline. Both Reissner–Mindlin and Kirchhoff–Love assumptions are considered in the case of static bending and free vibration analysis of thin-walled structures (plates and shells). The convergence behaviors of these two assumptions for both plate and shell are thoroughly studied and compared. The discrete formulations for large deformation of Kirchhoff–Love shells considering geometrical and material nonlinearity are detailedly derived and carefully implemented. Three types of hyperelastic materials, including St. Venant–Kirchhoff, incompressible neo-Hookean and compressible neo-Hookean, are employed in the large deformation of Kirchhoff–Love shells. A series of popular benchmark examples and their geometrical models are demonstrated in the package. The numerical results are validated by comparing with analytical solutions and that obtained from commercial software. The postprocessing is self-contained and implemented by tessellation of Bézier elements. Finally, complete source codes and the data obtained from numerical examples are fully provided and free to access.

A decoupled SPH-FEM analysis of hydrodynamic wave pressure on hyperbolic-paraboloid thin-shell coastal armor and corresponding structural response

Kinetic Umbrella, an innovative thin-shell structural system, incorporating hyperbolic paraboloid (hypar) geometry, has been proposed for coastal hazard mitigation. Its feasibility against surge and wave loadings has been conceptually validated via a Hurricane Sandy case study. However, the typical hydrodynamic wave pressure on hypar geometries and the rationality of the previously conducted static structural analyses remain unknown. In response, this paper implements a decoupled numerical scheme consisting of smoothed particle hydrodynamics (SPH) and finite element modeling (FEM), investigating the hydrodynamic wave pressure and corresponding structural response via structural dynamic analyses. Furthermore, the accuracy of applying the hydrodynamic wave pressure predicted by the well accepted Goda’s formula to the structural analysis of Kinetic Umbrellas is also evaluated. The results show that the hydrodynamic wave pressure on hypar follows a bilinear like shape along height and increases gradually from the edge of the hypar to the longitudinal spine. The hydrodynamic wave pressure difference between the edge and the longitudinal spine will be intensified by higher warping magnitude of hypar and under breaking waves. For structural response, the maximum displacement and the maximum tensile membrane force of the shell are significantly underestimated by static analyses with Goda’s formula, implying the necessity of implementing the decoupled SPH-FEM scheme with structural dynamic analyses. For other critical demands, the difference is mostly smaller than 20%. The findings reinforce the idea that hypar thin shells are structurally feasible under surge and wave loadings, and ultimately facilitate the employment of hypar thin shells for coastal defense as a sustainable alternative to traditional coastal structures.

Finite Element Analysis of Super Austenitic Stainless-Steel Flange

In this paper structural analysis and topological optimization of bolted joint Flange fitting using Super Austenitic Stainless Steel have been studied in order to achieve effective structural design. Flange fittings are used to connect pipes, pumps, valves, shafts and supporting structures where the connection between two flanges is very prone to corrosion. The failure of one of these connections could cause severe damage. In this study FEA analysis has been performed on flange fitting using Super Austenitic Stainless Steel. The current work has been initiated from designing a 3D model of Flange Fitting in Auto-Cad which then imported to Ansys Design Modeller for structural, modal analysis and topological optimization. Static structural analysis is usually done for finding overall strength of the design. Equivalent stresses (Von Mises), Total deformations and modal analysis on Flange fitting of Alloy steel and Super Austenitic Stainless Steel (UNS S31254) have been evaluated for checking the stability of the flange fitting. The aim of this study is to reduce the weight of the flange fitting using mass reduction as a constraint in topological optimization. A comparative result between optimized design and original design has been described within this study.

Design and Analysis of Cost reduced Diesel Exhaust Aftertreatment system against Flex Module

Abstract : This research paper represents Designing of Cost reduced Diesel Exhaust Aftertreatment system against existing Flex Module aftertreatment system. Methods represents the steps to design new cost reduced Aftertreatment system. Study involves how new design is still meeting existing space claim and meeting all performance requirements. Simsolid software were used to calculated Modal and Static structural analysis to compare both the designs & ARAI test facility has been used to validate new deign meets Emission compliance as per BS6 Limit for MHCV Norms.

Design, Analysis of Car Knuckel by using ANSYS Workbench

Abstract: Steering knuckle is an indispensable part of an automobile vehicle, integrating different subsystems like suspension, brakes and steering. Being the pivot point of the vehicle, it undergoes diverse stacking under rigorous conditions resulting in failure of the component. The objective of this paper is to perform static structural analysis on the knuckle under diverse loadings. This is achieved by designing a generic steering knuckle of a car in CATIA V5R20 and performing the finite element analysis using ANSYS Workbench 14.5. The analysis is carried out under maximum loading condition, braking and bump maneuvering.

3D printed human humerus bone with proximal implant prototype for arthroplasty

Human shoulder joints are susceptible to failure due to Osteonecrosis. It occurs at the humeral head region thereby collapsing it. For repair, resurfacing arthroplasty is used which involves reshaping of the humerus bone head and preparing an implant. But it is a tedious process to prepare the bone implant conventionally. This article presents developing prototype of a customized implant on human humerus bone that can act as an alternative to the conventional manufacturing of implants. 3D scanning technology is employed for acquisition of data of humerus bone in the form of point cloud which acts as an input for its modeling. Morphometric measurements of the bone are used to develop the resurfacing implant for proximal humerus. The humerus head is reshaped using Boolean operations and assembled with resurfacing implant. CATIA software is used for CAD modeling and related operations. Static structural analysis is performed on humerus bone and reshaped humerus bone with implant in ANSYS software to know its behaviour during different loading conditions. Fused Deposition Modeling technology has been used for 3D printing of humerus bone and its implant. However, the procedure for geometric modeling of such complex shape bone and its proximal implant has not been well defined.

Unexpected steric hindrance failure in the gas phase F− + (CH3)3CI SN2 reaction

Base-induced elimination (E2) and bimolecular nucleophilic substitution (SN2) reactions are of significant importance in physical organic chemistry. The textbook example of the retardation of SN2 reactivity by bulky alkyl substitution is widely accepted based on the static analysis of molecular structure and steric environment. However, the direct dynamical evidence of the steric hindrance of SN2 from experiment or theory remains rare. Here, we report an unprecedented full-dimensional (39-dimensional) machine learning-based potential energy surface for the 15-atom F− + (CH3)3CI reaction, facilitating the reliable and efficient reaction dynamics simulations that can reproduce well the experimental outcomes and examine associated atomic-molecular level mechanisms. Moreover, we found surprisingly high “intrinsic” reactivity of SN2 when the E2 pathway is completely blocked, indicating the reaction that intends to proceed via E2 transits to SN2 instead, due to a shared pre-reaction minimum. This finding indicates that the competing factor of E2 but not the steric hindrance determines the small reactivity of SN2 for the F− + (CH3)3CI reaction. Our study provides new insight into the dynamical origin that determines the intrinsic reactivity in gas-phase organic chemistry.

Experimental and numerical study on the mechanical properties of honeycomb plate box-type hollow roof structure

In this paper, a new honeycomb plate box-type hollow roof structure is prepared. The failure mode and mechanical properties of the box-type hollow roof structure were analyzed by bearing capacity test and numerical analysis. The validity of the numerical analysis model is verified by comparing the results of bearing capacity test with the results of the complete coordinated model and the coupled model analysis. The results show that the failure mode of the specimen is tensile failure of the surface plate of the honeycomb plate with strengthened frame and buckling instability of the plate near the joint. The box-type hollow roof structure has good ductility. The results of static analysis and nonlinear buckling analysis of the honeycomb plate box-type hollow roof structure are carried out by coupling model are more consistent with the results of bearing capacity test.

Topology optimization and lightweight design of stamping dies for forming automobile panels

Accurate prediction of deformation and stress distribution on stamping die components is critical to guarantee structure reliability and lightweight design. This work aims to propose a new method for predicting die structural behaviors and reducing total weight based on numerical simulation. Sheet metal forming simulation was firstly conducted to obtain the accurate forming contact force. The linear static structural analyses under different load conditions were performed to investigate the deformation and stress distribution of the die structure. Topology optimization was employed to realize the lightweight design on the premise of ensuring structural safety. According to the manufacturing techniques and initial optimization results, the die structure was redesigned to guarantee the manufacturability of the new structure. The proposed methodology has several advantages of decreasing model scale, precluding intricate contact condition settings as well as time saving. A long beam stamping die used for forming automobile panels was selected to validate the proposed methodology, and about 18% weight reduction was achieved.

Reinforced Metal Bipolar Plate Structure with Stiffening Rib Channel for Proton Exchange Membrane Fuel Cell

Clean energy has become a concern because fossil fuels are the primary cause of climate change and air pollution. A proton exchange membrane fuel cell (PEMFC) is an environmentally friendly vehicle's alternative energy source. Bipolar plates, gaskets, gas diffusion layers, and a membrane electrode assembly (MEA) constitute a PEMFC. The bipolar plate accounts for a large portion of the fuel cell stack cost. Metallic bipolar plates are utilized in vehicle fuel cell stacks because of its low fabrication cost, high manufacturability, mechanical strength, and low weight. Despite the benefits, a thin metal plate's major drawbacks are deformation and corrosion resistance.Stamping metallic plates form trapezoidal cross-section channels, whereas machined graphite bipolar plates can form rectangular cross-section channels. These trapezoidal channels make dimensional errors such as draft angle and fillet radius. Besides, the spring back effect makes shape errors in the manufacturing process. Many kinds of research are conducted to understand the impact of channel tolerances on the performance of PEMFCs. Mainly, inhomogeneous compression in the gas diffusion layer results from channel deformation caused by unevenly distributed clamping force and shape inaccuracy of the metal bipolar plates. High contact resistance and non-uniform reactant gas distribution would result from inhomogeneous compression of GDL.A reinforced metal bipolar plate structure with a stiffening rib channel is proposed in this work to reduce bipolar plate deformation and improve gas transfer. Stiffening ribs are imprinted on the top of the channel. The geometric parameters of the stiffening ribs are shown in Fig. 1. Four geometric design parameters are selected in this study, the distance between the ribs d1, length of the rib l1, height of the rib l2, width of the rib l3. The stainless steel with a thickness of 0.1mm, 50mm×50mm active area, is used. The influence of stiffening ribs on mechanical and fluid characteristics is investigated through numerical analyses and experiments. The static structural analysis illustrated the deformation of the bipolar plates and GDL under the clamping force. The stiffening rib design improves the structure's mechanical strength, lowering bipolar plate deformation. When the endplates clamp the stack, the stiffening rib supports more stress to prevent deformation. The flow distribution in the flow field channel and GDL was then visualized using computational fluid analysis. Stiffening ribs increase the velocity of the reactant. Enhanced under rib convection makes reactant gas evenly distributed. In addition, stiffening ribs causes a convective flow beneath the rib, which improves PEMFC performance. Finally, single-cell studies proved that the modeling results are valid. Under the same operating conditions with the same geometry to the model, electrochemical reactions are investigated to decouple the leading cause of the resistances. The ohmic resistance decreases with the robust structural stiffening ribs, and the mass transport resistance decreases with the well-distributed reactants flow. Figure 1

The finite element modeling of the impacting process of hard particles on pump components

Abstract Shield pumps which transport a variety of complex media are widely used in chemical industry, mineral industry, and other fields. However, the hard particles in the media erode the flow passage in the shield pump, seriously affecting the service life of the pump. Therefore, it is important to study the erosion process in the flow passage to extend the service life of the pump. This erosion process in the shield pump can be investigated by experiments, but it is difficult for the current experimental method to copy the real industrial service environment of impellers. For example, the environment temperature and speed range are found difficult to be reached by the current experimental method. Comparatively, the simulation by finite element method can overcome the above deficiency. In this article, the ANASYS software is used to simulate the erosion process in shield pump flow passage due to hard particles. Specifically, the structural static analysis module is used to build the model of thermal barrier coating components and hard particle components. Then the variation law of stress, strain, and material deformation of the flow passage components under concentrated force is obtained. Second, the extended finite element method is used to study the crack propagation caused by the erosion process. A linear elastic–linear softening constitutive model is established to simulate the stress variation during the crack propagation and material removal under the continuous erosion from hard particles. The proposed law regarding stress variation and crack propagation in the erosion process in this study contributes to theoretical support for damage detection and service life extension of shield pumps.

Simulation studies on the comparison of different superalloys used in gas turbine blades

Impingement of gases at high temperature and pressure leads to the development of stresses and deformation in gas turbine blades. Other important characteristics are also getting changed, prompting more problems in gas turbine engines, as they are used in both power generation and transportation. In this work, failure aspects in blades is studied by performing structural analysis, considering superalloys that are used in the industry. Software packages like Solidworks and Ansys are used for modelling, meshing and solving, in order to identify the target variables like total deformation, von Mises stress, strain energy and fatigue. Geomtery of the turbine blade is modelled and after meshing, boundary conditions like pressure, force and rotational speed are enforced. Results are analysed after carrying out the static structural analysis in Ansys work bench. For the superalloy materials chosen, contours and plots are made for all the configurations. Validation of deformation from the present work is done with experiments done earlier, which is in good agreement. Total deformation is more at the tip of the blade. At the root of the blade, the stresses are found to be more. Presence of strain energy is more near the root. Fatigue life contours showed similarity in all the cases. The blade failure region is identified for all the materials under consideration and the trends are compared for different input temperatures. Thus the current work is helpful in recognizing appropriate superalloy to be used in the present day gas turbines and supports the use of GTD 111 as gas turbine blade material.

STRUCTURE ROBUSTNESS AGAINST PROGRESSIVE COLLAPSE DUE TO UNFORESEEABLE EVENTS

A robust structure will survive and remain serviceable during its design life where unforeseeable events or attacks are likely to occur. Examples of such unforeseeable events are: change of use; sudden and large settlements of supports; extreme impact; war; fire; extreme wind; catastrophic events, etc. Two case studies are presented in this paper, a multi-story flat plate building subjected to column loss and a cable-stayed bridge subjected to cable(s) loss, in order demonstrate such a role of robustness. The finite element method considering both material and geometric nonlinearity, with the aid of the software ABAQUS, is employed in this study to perform both static and dynamic analysis of the relevant structures. The two examples reveal how robustness can prevent progressive collapse of structures due to unforeseeable events. The flat plate building with continuous bottom reinforcement could survive column loss. The system robustness enabled the cable-stayed bridge to survive cable(s) loss.

Design and development of large scale FDM based 3D printer

Additive Layer Manufacturing (ALM) is one of the fabricating methods because it permits outrageous customization, quick prototyping of wanted designs and low volume creation of items. FDM printer goes under the material expulsion class. The filament is constrained into the hot extruder. The filament is warmed first and afterward stored, through the spout, onto a form stage layer-by-layer to frame the total 3D structure. A printer equipped for printing a 1.5-meter cubic-sized object was designed in SOLIDWORKS CAD software and manufactured into a functioning model. The Frame, Linear guide rail, and Z-axis rails were subjected to static structural, modal and harmonic response analysis with ANSYS Workbench. The designed parts were investigated by modal analysis to get the natural frequency. The effect on the guide rails and frame due to external forces, stepper motor, and extruder were examined with harmonic response analysis. The frequency at which the amplitude rises drastically from a phase angle of 0 degrees to 180 degrees was obtained using harmonic response analysis as well. The model was further subjected to motion analysis using ADAMS dynamic software.