Design and Fatigue Life Analysis of a Motorcycle Frame

Author(s):  
Massimiliano Gobbi ◽  
Giorgio Previati ◽  
Giampiero Mastinu

An off-road motorcycle frame has been analyzed and modified to optimize its fatigue life. The fatigue life of the frame is very important to define the service life of the motorcycle. The strain levels on key parts of the frame were collected during experimental tests. It has been possible to locate the areas where the maximum stress level is reached. A finite element (FE) model of the frame has been developed and used for estimating its fatigue life. Static test bench results have been used to validate the FE model. The accuracy of the finite element model is good, the errors are always below 5% with respect to measured data. The mission profile of the motorcycle is dominated by off-road use, with stress levels close to yield point, so a strain-life approach has been applied for estimating the fatigue life of the frame. Particular attention has been paid to the analysis of the welded connections. A shell and a 3D FE model have been combined to simulate the stress histories at the welds. Two reference maneuvers have been considered as loading conditions. The computed stresses have been used to assess the life of the frame according to the notch stress approach (Radaj & Seeger). The method correlates the stress range in a idealized notch, characterized by a fictitious radius in the weld toe or root, to the fatigue life by using a single S-N curve. New technical frame layouts have been proposed and verified by means of the developed finite element model. The considered approach allows to speed up the design process and to reduce the testing phase.

2018 ◽  
Vol 51 (3) ◽  
pp. 15-40
Author(s):  
Marsel Garifullin ◽  
Sami Pajunen ◽  
Kristo Mela ◽  
Markku Heinisuo

Major developments in hardware and software enable researchers and engineers to apply non-linear finite-element analyses to study the behavior of tubular structures. However, to provide reasonable results, constructed finite element models should be verified and validated with experimental data. This article develops a finite element model for high strength steel rectangular hollow section T joints. The joints are considered under in-plane bending moment and axial brace loading. The paper determines the most suitable finite elements and the number of layers in the thickness direction for the numerical assessment of initial stiffness and modeling the whole action-deformation behavior of joints. Finally, the proposed FE model is validated with the series of experimental tests. The validation shows that the developed model properly captures the local behavior of tubular joints and can efficiently serve as a reliable tool in routine numerical analyses.


2021 ◽  
pp. 136943322110073
Author(s):  
Yu Cheng ◽  
Yuanlong Yang ◽  
Binyang Li ◽  
Jiepeng Liu

To investigate the seismic behavior of joint between special-shaped concrete-filled steel tubular (CFST) column and H-section steel beam, a pseudo-static test was carried out on five specimens with scale ratio of 1:2. The investigated factors include stiffening types of steel tube (multi-cell and tensile bar) and connection types (exterior diaphragm and vertical rib). The failure modes, hysteresis curves, skeleton curves, stress distribution, and joint shear deformation of specimens were analyzed to investigate the seismic behaviors of joints. The test results showed the connections of exterior diaphragm and vertical rib have good seismic behavior and can be identified as rigid joint in the frames with bracing system according to Eurocode 3. The joint of special-shaped column with tensile bars have better seismic performance by using through vertical rib connection. Furthermore, a finite element model was established and a parametric analysis with the finite element model was conducted to investigate the influences of following parameters on the joint stiffness: width-to-thickness ratio of column steel tube, beam-to-column linear stiffness ratio, vertical rib dimensions, and axial load ratio of column. Lastly, preliminary design suggestions were proposed.


2013 ◽  
Vol 456 ◽  
pp. 576-581 ◽  
Author(s):  
Li Fu Xu ◽  
Na Ta ◽  
Zhu Shi Rao ◽  
Jia Bin Tian

A 2-D finite element model of human cochlea is established in this paper. This model includes the structure of oval window, round window, basilar membrane and cochlear duct which is filled with fluid. The basilar membrane responses are calculated with sound input on the oval window membrane. In order to study the effects of helicotrema on basilar membrane response, three different helicotrema dimensions are set up in the FE model. A two-way fluid-structure interaction numerical method is used to compute the responses in the cochlea. The influence of the helicotrema is acquired and the frequency selectivity of the basilar membrane motion along the cochlear duct is predicted. These results agree with the experiments and indicate much better results are obtained with appropriate helicotrema size.


Author(s):  
Zhenguo Lu ◽  
Lirong Wan ◽  
Qingliang Zeng ◽  
Xin Zhang ◽  
Kuidong Gao

Conical picks are the key cutting components used on roadheaders, and they are replaced frequently because of the bad working conditions. Picks did not meet the fatigue life when they were damaged by abrasion, so the pick fatigue life and strength are excessive. In the paper, in order to reduce the abrasion and save the materials, structure optimization was carried out. For static analysis and fatigue life prediction, the simulation program was proposed based on mathematical models to obtain the cutting resistance. Furthermore, the finite element models for static analysis and fatigue life analysis were proposed. The results indicated that fatigue life damage and strength failure of the cutting pick would never happen. Subsequently, the initial optimization model and the finite element model of picks were developed. According to the optimized results, a new type of pick was developed based on the working and installing conditions of the traditional pick. Finally, the previous analysis methods used for traditional methods were carried out again for the new type picks. The results show that new type of pick can satisfy the strength and fatigue life requirements.


2011 ◽  
Vol 3 (2) ◽  
pp. 57-64
Author(s):  
LOZICI-BRÎNZEI Dorin ◽  
◽  
TǍTARU Simion ◽  
BÎSCĂ Radu

Author(s):  
Jean-Jacques Sinou ◽  
David Demailly ◽  
Cristiano Villa ◽  
Fabrice Thouverez ◽  
Michel Massenzio ◽  
...  

This paper presents a research devoted to the study of vibration problems in turbofan application. Several numerical and experimental tools have been developed. An experimental test rig that simulates the vibrational behavior of a turbofan engine is presented. Moreover, a finite element model is used in order to predict the non-linear dynamic behavior of rotating machines and to predict the first critical speed of engineering machine. A comparison between the experimental tests and the numerical model is conducted in order to evaluate the critical speed of the rotating structure and to update the finite element model.


Author(s):  
Babak Ebrahimi ◽  
Amir Khajepour ◽  
Todd Deaville

This paper discusses the modeling and analysis of a novel audio subwoofer system for automotive applications using the automobile windshield glass. The use of a piezo-electric actuator coupled with a mechanical amplifier linked to a large glass panel provides a highly efficient method of producing sound. The proposed subwoofer system has the advantage over existing conventional systems of not only reducing the weight of the automobile, but also a significant power savings resulting in an increase of expected fuel economy. Among various design challenges, the glass-sealing design is of huge importance, as it affects the system dynamic response and so the output sound characteristics. The main goal in this manuscript is to evaluate different glass-sealing design configurations by providing a comprehensive Finite Element model of the system. To do so, a comprehensive, yet simplified FE model is developed, and experimental studies are performed in the component level to fine-tune and verify the model. Harmonic response of the system for each sealing configuration design is obtained in the frequency range of 0–200 Hz, and the results are compared and discussed. The finite element model is also beneficial in preliminary design of other components as well as the exciter placement, and predicting the performance of the overall system.


Author(s):  
Lili Zhang ◽  
Tingli Xie ◽  
Jiexiang Hu ◽  
Ping Jiang ◽  
Jasuk Koo ◽  
...  

Abstract In this study, an additive scaling function based multi-fidelity (ASF-MF) surrogate model is constructed to fast predict fatigue life as well as the stress distribution for the welded single lap joint. The influence of leg length, leg height, the width of the specimen and load in the fatigue test are taken into consideration. In the construction of the MF surrogate model, the finite element model that is calibrated with the experiment is chosen as the high-fidelity (HF) model. While the finite element model that is not calibrated with the experiment is considered as the low-fidelity (LF) model, aiming to capture the trend of the HF model. The Leave-one-out (LOO) verification method is utilized to compare the prediction performance of the ASF-MF surrogate model with that of the single-fidelity Kriging surrogate model. Results show that the ASF-MF surrogate model can better predict the fatigue life as well as the stress distribution.


Author(s):  
Michaël Martinez ◽  
Sébastien Montalvo

Abstract The mooring of floating platforms is an important challenge for the offshore industry. It is an important part of the design engineering and, often, a critical point for the fatigue life assessment. A solution that could improve the fatigue life is to directly connect the mooring rope to the platform, without an intermediate chain. However this solution is not widespread and the behavior of a rope near such a connection is little known. The present paper proposes to better understand this behavior, thanks to a detailed finite element model of the rope. The study case is a steel wire rope directly connected to a floating wind turbine. A local finite element model of the rope has been built, where the wires are individually modeled with beam elements. One end of the rope is clamped, simulating the connection, while tension and cyclic bending oscillations are applied to the other end. A localized bending takes place near the connection, leading to stress concentration in the wires. The stress concentration and the local contact forces are calculated for each wire. These data are important entry parameters for a local failure or fatigue analysis. This latter is however not presented here. Despite IFPEN experience in the development of local finite element models of steel wire ropes, it is the first time that such a high capacity rope (MBL = 12 500 kN) is modeled. This is challenging because of the large diameter of the rope and the large number of wires. However this modeling approach is very valuable for such ropes, because the experimental tests are rare and very expensive.


Author(s):  
John M. Emery ◽  
Jeffrey E. Bozek ◽  
Anthony R. Ingraffea

The fatigue resistance of metallic structures is inherently random due to environmental and boundary conditions, and microstructural geometry, including discontinuities, and material properties. A new methodology for fatigue life prediction is under development to account for these sources of randomness. One essential aspect of the methodology is the ability to perform truly multiscale simulations: simulations that directly link the boundary conditions on the structural length scale to the damage mechanisms of the microstructural length scale. This presentation compares and contrasts two multiscale methods suitable for fatigue life prediction. The first is a brute force method employing the widely-used multipoint constraint technique which couples a finite element model of the microstructure within the finite element model of the structural component. The second is a more subtle, modified multi-grid method which alternates analyses between the two finite element models while representing the evolving microstructural damage. Examples and comparisons are made for several geometries and preliminary validation is achieved with comparison to experimental tests conducted by the Northrop Grumman Corporation on a wing-panel structural geometry.


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