Calculation and study of the failure of the connecting-rod small end based on thermoelastic plasticity

2016 ◽  
Vol 231 (11) ◽  
pp. 1489-1499
Author(s):  
Guohua Chen ◽  
Ridong Liao ◽  
Xue Jiang
Keyword(s):  
Contact Force ◽  
Wall Thickness ◽  
Loading Condition ◽  
Thermal Loading ◽  
Operating Temperature ◽  
Thermomechanical Coupling ◽  
Plasticity Model ◽  
High Power Density ◽  
Connecting Rod ◽  
Interference Fit

In this study, the mechanisms that cause bush loosening and rotation failure were studied on the connecting-rod small end of a high-power-density engine. Using the thermoelastic plasticity model and the thermomechanical coupling method, the stress field and the assembly contact force of the connecting-rod small end were predicted by considering four different loading conditions: first, the initial loading condition; second, the thermal loading condition; third, the mechanical loading condition; fourth, the unloading condition. This process showed the effects of the initial interference fit, the operating temperature and the wall thickness of the bush on the assembly contact force. It was found that, first, a large interference leads to a small assembly contact force after unloading, second, a higher operating temperature significantly reduces the assembly contact force and, third, the wall thickness of the bush has little influence on the assembly contact force. In conclusion, a high operating temperature is the main cause of bush loosening and rotation. This conclusion was validated by the experimental results. On the basis of this study, it is suggested that the operating temperature is limited in order to maintain the reliability of the connecting-rod small end.

Report of the Automobile Research Committee on Contraction of Aluminium Alloy Bearings

1945 ◽  
Vol 40 (2) ◽  
pp. 205-228
Author(s):  
L. Farkas ◽  
H. Ludicke
Keyword(s):  
Aluminium Alloy ◽  
Wall Thickness ◽  
Effect Of Temperature ◽  
Connecting Rod ◽  
Research Committee ◽  
Bearing Material ◽  
Interference Fit ◽  
Set Up ◽  
Bearing Alloy ◽  
And Control

The nature and the causes of contraction of aluminium alloy bearings have been investigated. Previous test results indicated that contraction is due to plastic straining of the bearing material. This is confirmed by calculation of the stresses set up in the bearing alloy, which are caused by the interference fit between bearing and housing and the differential thermal expansion of aluminium alloy and steel. The variables affecting bearing contraction are then considered under the headings:—( a) Strength of material; ( b) interference fit; ( c) bearing wall thickness; ( d) bearing size; ( e) connecting-rod wall thickness. Finally, the effect of temperature upon bearing clearance is considered. The results show that contraction can be prevented by a suitable choice of the bearing material and control of the dimensions. In particular, the interference fit should be kept low, and an alloy should be used which has a relatively high elastic limit in compression. The application of the results may be extended to light alloy bearings in general and for both bush type and split bearings fitted in steel housings.

Optimization of the Wrist Pin End of an Automobile Engine Connecting Rod With an Interference Fit

1990 ◽  
Vol 112 (3) ◽  
pp. 406-412 ◽  
Author(s):  
Vijay Sarihan ◽  
Ji Oh Song
Keyword(s):  
Finite Element ◽  
Optimum Design ◽  
Three Dimensional ◽  
Stress Singularity ◽  
Design Strategy ◽  
Structural Components ◽  
Connecting Rod ◽  
Fem Model ◽  
Automobile Engine ◽  
Interference Fit

Current design procedures for complicated three-dimensional structural components with component interactions may not necessarily result in optimum designs. The wrist pin end design of the connecting rod with an interference fit is governed by the stress singularity in the region where the wrist pin breaks contact with the connecting rod. Similar problems occur in a wide variety of structural components which involve interference fits. For a better understanding of the problems associated with obtaining optimum designs for this important class of structural interaction only the design problems associated with the wrist pin end of the rod are addressed in this study. This paper demonstrates a procedure for designing a functional and minimum weight wrist pin end of an automobile engine connecting rod with an interference fit wrist pin. Current procedures for Finite Element Method (FEM) model generation in complicated three-dimensional components are very time consuming especially in the presence of stress singularities. Furthermore the iterative nature of the design process makes the process of developing an optimum design very expensive. This design procedure uses a generic modeler to generate the FEM model based on the values of the design variables. It uses the NASTRAN finite element program for structural analysis. A stress concentration factor approach is used to obtain realistic stresses in the region of the stress singularity. For optimization, the approximate optimization strategy in the COPES/CONMIN program is used to generate an approximate design surface, determine the design sensitivities for constrained function minimization and obtain the optimum design. This proposed design strategy is fully automated and requires only an initial design to generate the optimum design. It does not require analysis code modifications to compute the design sensitivities and requires very few costly NASTRAN analyses. The connecting rod design problem was solved as an eight design variable problem with five constraints. A weight reduction of nearly 27 percent was achieved over an existing design and required only thirteen NASTRAN analyses. It is felt that this design strategy can be effectively used in an engineering environment to generate optimum designs of complicated three-dimensional components.

Accuracy of CMOS-Based Piezoresistive Stress Sensor for Engineering Applications of Thermal Loading Condition: Theoretical Review and Experimental Validation

2019 ◽  
Vol 19 (20) ◽  
pp. 9139-9148 ◽  
Author(s):  
Alexandru Prisacaru ◽  
Alicja Palczynska ◽  
Przemyslaw Gromala ◽  
Bulong Wu ◽  
Bongtae Han ◽  
...  
Keyword(s):  
Loading Condition ◽  
Experimental Validation ◽  
Thermal Loading ◽  
Engineering Applications ◽  
Stress Sensor

Development of Honeycomb-Type Solid Oxide Fuel Cell Consisting of LaGaO3 Electrolyte

2007 ◽  
Vol 544-545 ◽  
pp. 969-972 ◽  
Author(s):  
Hao Zhong ◽  
Hiroshige Matsumoto ◽  
Tatsumi Ishihara ◽  
Akira Toriyama
Keyword(s):  
Power Density ◽  
Operating Temperature ◽  
Electrochemical Techniques ◽  
Polarization Current ◽  
High Power Density ◽  
A Value ◽  
Honeycomb Cell ◽  
First Time ◽  
Thermal Stability Of ◽  
Operating Temperature Range

La0.9Sr0.1Ga0.8Mg0.2O3 (LSGM) -based honeycomb cell was first time successfully built and operated in the case of single-wall used condition and the full 4-walls cell one. Power generation characteristic of this honeycomb cell was measured from 700°C to 900°C by using various electrochemical techniques including polarization, current interruption and impedance spectrometry. The LSGM honeycomb cell shows the exact high power density compared with the ZrO2 based cell at the operating temperature range, and its value is 394 and 252 mW/cm2 at 800°C and 700°C, respectively. Thermal stability of this honeycomb cell is also studied and it is seen that the good performance through several times thermal cycling is observed. The 4-walls’s cell stack is successfully working at 800°C, and the volumetric power density is achieved to a value of about 700 mW/cm3.

Novel SiC Zener Diodes with High Operating Temperature of 300°C and High Power Density of 40 kW/cm2

2008 ◽  
Vol 600-603 ◽  
pp. 1015-1018 ◽  
Author(s):  
Ryosuke Ishii ◽  
Koji Nakayama ◽  
Hidekazu Tsuchida ◽  
Yoshitaka Sugawara
Keyword(s):  
Temperature Coefficient ◽  
Power Density ◽  
Breakdown Voltage ◽  
High Power ◽  
Operating Temperature ◽  
Pulsed Power ◽  
High Power Density ◽  
Device Failure ◽  
Large Active Area ◽  
Power Operation

This paper reports on the achievement of high-power 4H-SiC Zener diodes which have a high-doped pn junction with a large active area of 4 mm x 4 mm. The temperature coefficient of the breakdown voltage is as small as 5.7x10-5 1/K (positive) in the temperature range 20-300°C. In addition, reverse power capabilities of 6.3 kW (40 kW/cm2) at 20°C and 6.0 kW (38 kW/cm2) at 300°C during rectangular pulsed power operation (tw = 1 ms) have been achieved without device failure.

Practical Concerns for Adoption of Microjet Cooling

2018 ◽  
Author(s):  
Stephen M. Walsh ◽  
James P. Smith ◽  
Eric A. Browne ◽  
Timothy W. Hennighausen ◽  
Bernard A. Malouin
Keyword(s):  
Experimental Data ◽  
High Performance ◽  
Operating Temperature ◽  
Jet Impingement ◽  
Heat Fluxes ◽  
Liquid Jet ◽  
High Power Density ◽  
Lifetime Test ◽  
Large Heat ◽  
Power Densities

As power densities in advanced electronics continue to rise, the need for high performance thermal solutions becomes increasingly important. Liquid jet impingement has been applied to cooling high power-density electronics due to its ability to dissipate large heat fluxes while maintaining an acceptable operating temperature in the device. Recently, microjets have been embedded within the device substrate, forming a compact solution that is highly scalable. Many practical questions remain, however, on whether microjet technology is ready for actual implementation. In this work, we address several important questions that impede adoption of the technology. Numerical analysis and experimental data are provided to demonstrate the tradeoff between thermal performance and driving pressure requirements through pumping analysis. Additional mechanical concerns regarding robustness to clogging and resistance to erosion are addressed through a 1000-hour extended lifetime test.

Root Cause and FFS Analysis of a Dent in a 22mm Thick Elliptical Head

2018 ◽  
Author(s):  
Pascal Schreurs ◽  
Stan Kusters
Keyword(s):  
Wall Thickness ◽  
Operating Temperature ◽  
Local Buckling ◽  
Pressure Increase ◽  
Root Cause ◽  
Inner Pressure ◽  
Start Up ◽  
Level 3 ◽  
Inner Vessel ◽  
Thermal Oil

This paper describes the failure of a jacketed vessel. The product pressure is 16 barg (inner vessel; D = 2200 mm) and is heated with thermal oil in the jacket (operated at 4barg). The jacket is split up in different zones which can be opened and closed separately. After a shut down, several valves were not opened properly. This resulted in blocking-in of the jacket on the top head of the vessel during the start-up and operation of the vessel. The vessel was heated to the operating temperature (±250°C), causing a pressure increase of the blocked-in thermal oil. The jacket has a wall thickness of 10 mm, and the vessel head has a wall thickness of 22 mm. Because of the pressure increase, failure occurred at a nozzle weld on the inner pressure vessel shell. This resulted in a leakage of thermal oil into the vessel. The jacket itself deformed but did not fail. Based on a detailed FE analysis, it has been concluded that failure occurred as a result of (local) buckling of the 22mm thick elliptical head (diameter of ±2.200mm). This paper describes the failure that occurred and the assessments performed to determine and validate the root cause of the failure. A level 3 assessment according to ASME VIII div 2 Part 5 (1) was used to determine if the vessel is still safe for operation.

The Optimization of Small End Bushings of Connecting-Rod in Heavy-Load Diesel Engines

2014 ◽  
Vol 556-562 ◽  
pp. 1215-1219
Author(s):  
Song Yin ◽  
Wen Jie Qin
Keyword(s):  
Element Model ◽  
Radial Deformation ◽  
Connecting Rod ◽  
Heavy Load ◽  
Interference Fit ◽  
Safety Coefficient ◽  
Pareto Optimal Set ◽  
Approximate Mathematical Model ◽  
Set Up ◽  
Optimal Set

The mechanical fit between the connecting rod's small end and the bush is a typical interference fit. In this paper, an elastic-plastic finite element model of the assembly of the connecting rod and the bush is built based on ABAQUS simulation platform and simulation experiments are carried out by adopting the method of design of experiments. The magnitude of interference and the thickness of the bush are set as the test factors and the maximum radial deformation of the connecting rod’s small end hole, the radial contact pressure between the connecting rod and the bush, the plastic deformation of the bush and the fatigue strength safety coefficient of the connecting rod small end are set as the response variables. Based on the response surface equations, the multi-objective optimal approximate mathematical model is set up and the Pareto optimal set are gained and discussed.

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