scholarly journals Forensic Engineering Analysis of Failed UTV Roll Cages

2016 ◽  
Vol 33 (1) ◽  
Author(s):  
Olof Jacobson ◽  
Stephen A. Batzer ◽  
Mark Kittel ◽  
Jesse A. Grantham ◽  
Guy J. Barbera ◽  
...  
Keyword(s):  
Failure Modes ◽  
Dynamic Testing ◽  
Engineering Analysis ◽  
Cage Structure ◽  
Element Analysis ◽  
Design Concepts ◽  
Dirt Road ◽  
Analysis Laboratory ◽  
Forensic Engineering ◽  
Alternative Designs

Two cases were analyzed that involved pitchover/rollover accidents of the same model side by side utility terrain vehicle (UTV). In each case, the UTV ran over a bump on a dirt road and pitched over. The roll cages collapsed, and the drivers suffered significant injuries. Both roll cages collapsed in a similar manner. The design and failure modes of the roll cage structure were analyzed. Engineering analysis included dynamic analysis, laboratory testing, vehicle dynamic testing, finite element analysis, and a review of fundamental mechanical engineering design concepts. Roll cage design and applicable standards were evaluated. Reasonable alternative designs were identified and analyzed.

scholarly journals Non-Destructive Tests for the Structural Assessment of a Historical Bridge over the Tua River

2013 ◽  
Vol 569-570 ◽  
pp. 390-397 ◽  
Author(s):  
Isabel Valente ◽  
Luís F. Ramos ◽  
Kevin Vasquez ◽  
Paulo Guimarães ◽  
Paulo B. Lourenço
Keyword(s):  
Failure Modes ◽  
Dynamic Testing ◽  
Numerical Models ◽  
Dynamic Properties ◽  
Dynamic Test ◽  
Truss Structures ◽  
Design Standards ◽  
Element Analysis ◽  
Modern Design ◽  
Structural Assessment

Paradela Bridge is a metallic bridge located along the bank of the Tua River in northern Portugal. While the bridge is not currently in service, its structure is representative of many metallic truss structures built across the continent between the XIX and the XX century. Tua Line belongs to the Douro area that UNESCO recently declared as world heritage. This study acquires its importance since it might serve as an insight for the study of many other similar structures all over the country. This paper comprises a historic investigation of archived documents, an on-site survey to evaluate its present conditions, a dynamic testing and the construction and calibration of numerical models in finite element analysis (FEA) software, structural assessment and capacity rating estimation. The purpose of constructing numerical models was to evaluate the suitability of the bridge under the original loading and in accordance to modern design standards. The historical research revealed that the truss bridge was designed as a simply supported element and that a series of hand calculations were carried out on individual structural elements (e.g. main trusses, stringers and floor beams). Furthermore, a dynamic test was conducted in order to identify the global dynamic properties of the structure and to calibrate numerical models that ensure reliability and representativeness. FE models served through the structural assessment of the bridge in accordance with modern design codes and to estimate the safety of the bridge. Likewise, a nonlinear failure analysis was also conducted in order to estimate the capacity rate of the bridge and the likely failure modes.

scholarly journals Forensic Engineering Analysis of Design & Manufacturing Practices for an Automotive Spring

2017 ◽  
Vol 34 (1) ◽  
Author(s):  
John Leffler
Keyword(s):  
Quality Assurance ◽  
Control System ◽  
Failure Modes ◽  
Engineering Analysis ◽  
Vehicle Manufacturer ◽  
Apparent Absence ◽  
Automotive Control ◽  
Child Fatality ◽  
Forensic Engineering

A child fatality case focused on the failure of springs in an automotive control system switch. In the forensic engineering analysis, the actions of the spring manufacturer, switch manufacturer, control system manufacturer, and vehicle manufacturer were of interest. Relevant details included the spring manufacturing drawing, the spring design itself, the Design Failure Modes & Effects Analysis (DFMEA) conducted by the switch manufacturer, apparent absence of quality assurance testing, warranty return failure descriptions, and the actions taken by various entities upon notice of spring failures.

Accelerated testing of super lightweight UHPC waffle deck under heavy vehicle simulator

2021 ◽  
Vol 16 (2-3) ◽  
pp. 61-74
Author(s):  
Sahar Ghasemi ◽  
Amir Mirmiran ◽  
Yulin Xiao ◽  
Kevin Mackie
Keyword(s):  
High Performance ◽  
Failure Modes ◽  
High Performance Concrete ◽  
High Strength ◽  
Heavy Vehicle ◽  
Wheel Load ◽  
Element Analysis ◽  
Vehicle Simulator ◽  
Pavement Testing ◽  
Heavy Vehicle Simulator

A super lightweight deck can enhance load rating and functionality of a bridge, especially those identified as structurally deficient. This study was aimed to develop and experimentally validate a novel bridge deck as an ultra-lightweight low-profile waffle slab of ultra-high-performance concrete (UHPC) with either carbon fiber reinforced polymer (CFRP) or high strength steel (HSS) reinforcement. The proposed system lends itself to accelerated bridge construction, rapid deck replacement in bridges with load restrictions, and bridge widening applications without the need to replace girders. Performance and failure modes of the proposed deck were initially assessed through extensive lab experiments and finite element analysis, which together confirmed that the proposed deck panel meets the AASHTO LRFD requirements. The proposed deck system is not susceptible to punching shear of its thin slab and fails in a rather ductile manner. To evaluate its long-term performance, the system was further tested under the dynamic impact of wheel load at the Accelerated Pavement Testing (APT) facility of the Florida Department of Transportation using a Heavy Vehicle Simulator (HVS).

scholarly journals Design and analysis of concrete-filled tubular flange girders under combined loading

2021 ◽  
pp. 136943322110015
Author(s):  
Rana Al-Dujele ◽  
Katherine Ann Cashell
Keyword(s):  
Finite Element ◽  
Axial Force ◽  
Failure Modes ◽  
Numerical Study ◽  
Combined Loading ◽  
Torsional Stiffness ◽  
Fe Model ◽  
Combined Effects ◽  
Element Analysis ◽  
Hollow Section

This paper is concerned with the behaviour of concrete-filled tubular flange girders (CFTFGs) under the combination of bending and tensile axial force. CFTFG is a relatively new structural solution comprising a steel beam in which the compression flange plate is replaced with a concrete-filled hollow section to create an efficient and effective load-carrying solution. These members have very high torsional stiffness and lateral torsional buckling strength in comparison with conventional steel I-girders of similar depth, width and steel weight and are there-fore capable of carrying very heavy loads over long spans. Current design codes do not explicitly include guidance for the design of these members, which are asymmetric in nature under the combined effects of tension and bending. The current paper presents a numerical study into the behaviour of CFTFGs under the combined effects of positive bending and axial tension. The study includes different loading combinations and the associated failure modes are identified and discussed. To facilitate this study, a finite element (FE) model is developed using the ABAQUS software which is capable of capturing both the geometric and material nonlinearities of the behaviour. Based on the results of finite element analysis, the moment–axial force interaction relationship is presented and a simplified equation is proposed for the design of CFTFGs under combined bending and tensile axial force.

Appearance FMEA: A Method for Appearance Quality Evaluation of Early Design Concepts

2009 ◽  
Author(s):  
Karin Forslund ◽  
Timo Kero ◽  
Rikard So¨derberg
Keyword(s):  
Industrial Design ◽  
Failure Modes ◽  
Negative Impact ◽  
Consumer Products ◽  
Product Development Process ◽  
Early Design ◽  
Product Experience ◽  
Design Concepts ◽  
Quality Aspects ◽  
Noise Factors

For consumer products, early design stages are often concerned with the product’s industrial design, with primary focus on the consumer’s product experience. At this stage, aspects such as manufacturability and robustness are often not thoroughly taken into account. Industrial design concepts not properly suited for manufacture, assembly and process variability can result in final products in which the appearance intent is not satisfactorily realized. This can have a negative impact on the customer’s product quality perception. If such problems are discovered late in the product development process, late design changes and increased project costs may follow. The main difficulty in evaluating perceived quality aspects during industrial design is that the product is still under development. It is not mature enough to enable prediction of the prerequisites for achieving high manufacturing quality. In this paper, we suggest that concepts instead could be evaluated as far as the intrinsic tendency of the product appearance to support manufacturing variation and other noise factors. This is addressed through the concept of visual robustness: the ability of a product’s visual appearance to stimulate the same product experience despite variety in its visual design properties. Here, a method is suggested based on the Failure Modes and Effects Analysis (FMEA). The method follows a structured procedure for addressing appearance issues.

Preliminary Parametric Assessment of a Bolted Endplate Joint under Combined Axial Force and Cyclic Bending Moment

2011 ◽  
Vol 255-260 ◽  
pp. 718-721
Author(s):  
Z.Y. Wang ◽  
Q.Y. Wang
Keyword(s):  
Finite Element Analysis ◽  
Axial Force ◽  
Seismic Design ◽  
Axial Load ◽  
Failure Modes ◽  
Bending Moment ◽  
Element Analysis ◽  
Cyclic Behaviour ◽  
Joint Behaviour ◽  
Steel Joints

Problems regarding the combined axial force and bending moment for the behaviour of semi-rigid steel joints under service loading have been recognized in recent studies. As an extended research on the cyclic behaviour of a bolted endplate joint, this study is performed relating to the contribution of column axial force on the cyclic behaviour of the joint. Using finite element analysis, the deteriorations of the joint performance have been evaluated. The preliminary parametric study of the joint is conducted with the consideration of flexibility of the column flange. The column axial force was observed to significantly influence the joint behaviour when the bending of the column flange dominates the failure modes. The reductions of moment resistance predicted by numerical analysis have been compared with codified suggestions. Comments have been made for further consideration of the influence of column axial load in seismic design of bolted endplate joints.

Creep Simulation of the Hydroprocessing Reactor Using a Physically-Based CDM Model

2015 ◽  
Author(s):  
Yu Zhou ◽  
Chen Xuedong ◽  
Fan Zhichao ◽  
Jie Dong
Keyword(s):  
Damage Mechanics ◽  
Failure Modes ◽  
Elevated Temperatures ◽  
Three Dimensional ◽  
Critical Issue ◽  
Fe Modelling ◽  
Creep Failure ◽  
Good Tool ◽  
Element Analysis ◽  
Physically Based

Creep failure is one of the most important failure modes in the design of hydroprocessing reactors at elevated temperatures, and the accurate prediction of the creep behavior in structural discontinuities is a critical issue for component design. A physically-based continnum damage mechanics (CDM) model was adopted to describe all three creep stages of 2.25Cr-1Mo-0.25V ferritic steel widely used in manufacturing modern hydroprocessing reactors. The material constants in the damage constitutive equations were identified using an efficient optimization scheme based on genetic algorithm (GA). The user-defined subroutine implementing the CDM model was developed using user programmable features (UPFs) in ANSYS. Three-dimensional finite element analysis of the hydroprocessing reactor was conducted to determine the critical regions, and the studies on the stress redistribution and the prediction of damage evolution in these regions during creep were carried out. The results show that FE modelling based on CDM theory can provide a good tool for creep design of complex engineering components.

Experimental and theoretical study of sandwich composites with Z-pins under quasi-static compression loading

2021 ◽  
pp. 136943322110073
Author(s):  
Erdem Selver ◽  
Gaye Kaya ◽  
Hussein Dalfi
Keyword(s):  
Vinyl Ester ◽  
Failure Modes ◽  
Critical Role ◽  
Sandwich Composites ◽  
Test Results ◽  
Compressive Properties ◽  
Element Analysis ◽  
Static Compression ◽  
Quasi Static Compression ◽  
Good Agreement

This study aims to enhance the compressive properties of sandwich composites containing extruded polystyrene (XPS) foam core and glass or carbon face materials by using carbon/vinyl ester and glass/vinyl ester composite Z-pins. The composite pins were inserted into foam cores at two different densities (15 and 30 mm). Compression test results showed that compressive strength, modulus and loads of the sandwich composites significantly increased after using composite Z-pins. Sandwich composites with 15 mm pin densities exhibited higher compressive properties than that of 30 mm pin densities. The pin type played a critical role whilst carbon pin reinforced sandwich composites had higher compressive properties compared to glass pin reinforced sandwich composites. Finite element analysis (FE) using Abaqus software has been established in this study to verify the experimental results. Experimental and numerical results based on the capabilities of the sandwich composites to capture the mechanical behaviour and the damage failure modes were conducted and showed a good agreement between them.

Failure Analysis of Bamboo Bolt Connection in Uniaxial Tension by FEM by Considering Fiber Direction

2021 ◽  
Vol 71 (1) ◽  
pp. 58-64
Author(s):  
Raviduth Ramful
Keyword(s):  
Finite Element ◽  
Uniaxial Tension ◽  
Failure Modes ◽  
Damage Mechanism ◽  
Field Analysis ◽  
Fiber Direction ◽  
Element Formulation ◽  
Element Analysis ◽  
Test Standards ◽  
Lack Of Information

Abstract Full-culm bamboo has been used for millennia in construction. Specific connections are normally required to suit its unique morphology and nonuniform structure. Presently, the use of full-culm bamboo is limited in the construction industry as a result of a lack of information and test standards about the use and evaluation of full-culm connections. This study aims to further explore this area by investigating the failure modes in bamboo bolt connections in uniaxial tension by considering fiber direction in finite element analysis. Three types of bolt configurations of varying permutations, namely, single, dual, and orthogonal, were investigated. An orthotropic material was used as a constitutive model in finite element formulation to capture the inhomogeneity prevailing in bamboo culm. From the strain-field analysis of a hollow-inhomogeneous model representing bamboo, shear-out failure was dominant, as a localized area equivalent to the bolt diameter was affected due to high material orthotropy with high axial strength but weak radial and tangential strength. Bearing failure is assumed to precede shear-out failure at the bolt–bamboo contact interface, as the embedding strength was affected by localized strain concentration. The strain distribution in various bolt arrangements was found to vary between bolted connections of inhomogeneous-hollow geometry of bamboo and the ones of inhomogeneous-solid geometry representing timber. The observation in this study highlights the need for alternative design criteria to specifically assess the damage mechanism in bamboo connections.

scholarly journals The Bending Responses of Sandwich Panels with Aluminium Honeycomb Core and CFRP Skins Used in Electric Vehicle Body

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yong Xiao ◽  
Yefa Hu ◽  
Jinguang Zhang ◽  
Chunsheng Song ◽  
Xiangyang Huang ◽  
...  
Keyword(s):  
Electric Vehicle ◽  
Failure Modes ◽  
Sandwich Panels ◽  
Vehicle Body ◽  
Stacking Sequence ◽  
Honeycomb Core ◽  
Fibre Direction ◽  
Element Analysis ◽  
Honeycomb Sandwich ◽  
Carbon Fibre Reinforced Plastic

The aim of this paper was to investigate bending responses of sandwich panels with aluminium honeycomb core and carbon fibre-reinforced plastic (CFRP) skins used in electric vehicle body subjected to quasistatic bending. The typical load-displacement curves, failure modes, and energy absorption are studied. The effects of fibre direction, stacking sequence, layer thickness, and loading velocity on the crashworthiness characteristics are discussed. The finite element analysis (FEA) results are compared with experimental measurements. It is observed that there are good agreements between the FEA and experimental results. Numerical simulations and experiment predict that the honeycomb sandwich panels with ±30° and ±45° fibre direction, asymmetrical stacking sequence (45°/−45°/45°/−45°), thicker panels (0.2 mm∼0.4 mm), and smaller loading velocity (5 mm/min∼30 mm/min) have better crashworthiness performance. The FEA prediction is also helpful in understanding the initiation and propagation of cracks within the honeycomb sandwich panels.

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