外文翻譯--穩(wěn)態(tài)和瞬態(tài)工況下柴油機(jī)氣缸蓋應(yīng)力分布的實(shí)際測(cè)量與理論預(yù)測(cè)

1、中文 中文 7853 字， 字，4400 單詞 單詞出處： 出處：Lee K S, Assanis D N, Lee J, et al. Measurements and Predictions of Steady-State and Transient Stress Distributions in a Diesel Engine Cylinder Head[J]. Sae Technical Papers, 1999.本科畢業(yè)論文外

2、文文獻(xiàn)及譯文文獻(xiàn)、資料題目： Measurements and Predictions of Steady-State and Transient Stress Distributionsin a Diesel Engine Cylinder Head 文獻(xiàn)、資料來(lái)源：SAE 文獻(xiàn)、資料發(fā)表日期：1999.4 院 （部）：機(jī)電工程學(xué)院專(zhuān) 業(yè)： 班 級(jí)： 姓 名

3、： 學(xué) 號(hào)： 指導(dǎo)教師： 完成日期： 2suitable for rapid design and virtual prototyping of cylinder heads. The finite element method has been the foundation of many of the analyses that predict the thermal and stress fields within the

4、 cylinder head. However, the accuracy of such analyses critically depends on our understanding of the problem, and the accuracy of the boundary conditions used in the formulation. Thermal stresses are induced by any of t

5、he following causes： Temperature gradients under steady-state operation, including the effects of cyclic temperature changes in the combustion chamber wall An increase in the mean temperature of a component, which affect

6、s the expansion and distortion characteristics, thus inducing stresses Thermal shock loading resulting from a sudden change in speed or load during transients, which change the rate of heat flux from the gas to the cylin

7、der head.Due to the inherent difficulties in measuring stress fields near the critical regions on the firedeck surface, especially under transient conditions, limited sets of measurements that can shed light on the probl

8、em have been reported .A numerical study of thermal shock calculations by Keribar and Morel has shown that thermal waves propagate into components during engine transients, with the steepness of the front depending on ma

9、terial thermal properties. While for a ceramic component severe shock loads can cause surface compressive stresses to overshoot final steady-state values, the effect was not pronounced in higher conductivity materials. I

10、n order to validate this analytical finding, and attribute appropriately causes of failure in cast-iron cylinder heads, a combined experimental and analytical approach is followed here to study stress distributions under

11、 steady-state and transient operation. Experimental studies are conducted first to measure temperatures, heat fluxes and stresses under a series of steady-state and transient operating conditions. Both biaxial and uni-ax

12、ial high temperature strain gages have been inserted within the thermal penetration depth of a diesel engine cylinder head. The strain gage insertion beneath the surface of the firedeck ensures the durability and reliabi

13、lity of the sensor. At the same time, the placement within the thermal penetration depth allows for studying the effect of thermal shock loading under rapid transients, and for contrasting those measurements with corresp