柴油機(jī)關(guān)鍵件螺栓連接組合結(jié)構(gòu)非線性力學(xué)特性研究
發(fā)布時(shí)間：2019-01-08 14:14
【摘要】：由于墊片材料的非線性及組合結(jié)構(gòu)各部件之間接觸的非線性等多重非線性特性的影響,使得螺栓連接組合結(jié)構(gòu)的力學(xué)特性變得較為復(fù)雜。為了研究組合結(jié)構(gòu)整體力學(xué)特性,本文對螺栓法蘭墊片連接組合結(jié)構(gòu)的非線性靜動力學(xué)建模方法、組合結(jié)構(gòu)的準(zhǔn)靜態(tài)密封特性和動力學(xué)響應(yīng)機(jī)理等進(jìn)行了研究,具體研究內(nèi)容包括:1)考慮墊片材料非線性及各部件之間的接觸非線性,建立了組合結(jié)構(gòu)非線性靜力學(xué)有限元模型。得出了不同裝配連接工藝下螺栓殘余預(yù)緊力及墊片接觸壓力仿真計(jì)算結(jié)果。與試驗(yàn)測試結(jié)果進(jìn)行了對比,驗(yàn)證了仿真計(jì)算模型及計(jì)算結(jié)果的正確性,得到了滿足組合結(jié)構(gòu)密封特性要求的最優(yōu)螺栓裝配連接工藝。2)考慮氣缸墊材料非線性及接觸非線性,建立了柴油機(jī)關(guān)鍵件組合結(jié)構(gòu)非線性靜力學(xué)有限元模型。研究了不同裝配連接工藝對柴油機(jī)氣缸密封特性的影響,得到了滿足該高強(qiáng)化柴油機(jī)氣缸密封特性要求的最好缸蓋螺栓裝配連接工藝,為高強(qiáng)化柴油機(jī)關(guān)鍵件組合結(jié)構(gòu)氣缸密封特性的現(xiàn)代設(shè)計(jì)提供了指導(dǎo)。3)提出了無墊片及采用不同材料墊片的螺栓法蘭連接組合結(jié)構(gòu),計(jì)算了不同組合結(jié)構(gòu)的預(yù)應(yīng)力模態(tài)響應(yīng)頻率與振型。通過與相應(yīng)的組合結(jié)構(gòu)模態(tài)試驗(yàn)進(jìn)行對比,確定了模態(tài)仿真計(jì)算結(jié)果的準(zhǔn)確性。計(jì)算結(jié)果表明:與采用線彈性材料的鋁合金墊片相比,采用石墨填充金屬纏繞墊片,組合結(jié)構(gòu)前兩節(jié)彎曲模態(tài)頻率分別減小了13.5%和13.7%;組合結(jié)構(gòu)軸向具有不同的拉壓模態(tài)。4)發(fā)現(xiàn)了組合結(jié)構(gòu)軸向整體剛度具有明顯的拉壓非線性特性;提出將組合結(jié)構(gòu)的螺栓連接部位簡化等效為軸向雙彈簧-彎曲梁解析模型,發(fā)現(xiàn)了組合結(jié)構(gòu)螺栓連接部位在軸向也具有拉壓非線性剛度特性;當(dāng)組合結(jié)構(gòu)無墊片或者采用線彈性材料的鋁合金墊片時(shí),其軸向拉壓剛度都呈雙線性關(guān)系;當(dāng)采用非線性材料的石墨纏繞金屬墊片時(shí),其軸向拉壓剛度呈現(xiàn)很強(qiáng)的非線性關(guān)系。5)將組合結(jié)構(gòu)簡化為彈簧-質(zhì)量系統(tǒng),建立系統(tǒng)的振動控制方程,求解振動方程可知:在軸向載荷作用下,組合結(jié)構(gòu)只產(chǎn)生軸向振動。在橫向載荷作用下,當(dāng)彈簧軸向剛度分別為常數(shù)或者剛度為位移的一次函數(shù)且振動控制方程的質(zhì)量矩陣耦合時(shí),組合結(jié)構(gòu)只產(chǎn)生橫向轉(zhuǎn)角振動,當(dāng)彈簧軸向剛度分別為位移的一次函數(shù)且振動控制方程的質(zhì)量矩陣不耦合、彈簧剛度為雙線性和剛度為位移的二次函數(shù)時(shí),組合結(jié)構(gòu)產(chǎn)生橫縱耦合振動。在軸向和橫向耦合沖擊作用下,組合結(jié)構(gòu)也產(chǎn)生橫縱耦合振動。6)將墊片材料非線性及各部件之間的接觸非線性轉(zhuǎn)化為彈簧的軸向剛度非線性,建立了螺栓法蘭墊片連接組合結(jié)構(gòu)的軸向拉壓非線性剛度簡化動力學(xué)有限元模型;在軸向和橫向載荷分別作用下,對組合結(jié)構(gòu)簡化動力學(xué)模型進(jìn)行了有限元仿真計(jì)算,得到了組合結(jié)構(gòu)軸向及橫向振動特性。結(jié)果表明:簡化動力學(xué)模型的有限元計(jì)算結(jié)果與機(jī)理模型的解析分析結(jié)果具有較好的一致性。設(shè)計(jì)了組合結(jié)構(gòu)瞬態(tài)動力學(xué)沖擊試驗(yàn),驗(yàn)證了所提出的組合結(jié)構(gòu)非線性簡化動力學(xué)模型和機(jī)理分析模型的正確性,并在現(xiàn)象上驗(yàn)證了動力學(xué)機(jī)理模型的理論預(yù)測。7)采用非線性彈簧單元,對某高強(qiáng)化柴油機(jī)關(guān)鍵件組合結(jié)構(gòu)的缸蓋螺栓連接部位進(jìn)行重新建模,將彈簧單元的軸向剛度非線性納入到柴油機(jī)關(guān)鍵件組合結(jié)構(gòu)的整體動力學(xué)分析中;對該柴油機(jī)關(guān)鍵件組合結(jié)構(gòu)進(jìn)行了整體動力學(xué)計(jì)算;首次預(yù)測出在軸向沖擊下組合結(jié)構(gòu)只出現(xiàn)較大的軸向位移,在橫向沖擊下組合結(jié)構(gòu)產(chǎn)生橫縱耦合振動;驗(yàn)證了本文的提出的非線性簡化動力學(xué)建模方法更為安全可靠。
[Abstract]:The mechanical properties of the bolt-connecting composite structure become more complex due to the influence of the non-linearity of the gasket material and the non-linearity of the contact between the components of the combined structure. In order to study the overall mechanical properties of the composite structure, this paper studies the nonlinear static dynamic modeling method of the bolt flange gasket joint structure, the quasi-static sealing property and the dynamic response mechanism of the combined structure, and the specific research contents include: 1) Considering the non-linearity of the gasket material and the contact non-linearity between the components, the nonlinear static finite element model of the composite structure is established. The residual pre-tightening force of the bolt and the simulation result of the contact pressure of the gasket are obtained. compared with the test results, the correctness of the simulation calculation model and the calculation result is verified, and the optimal bolt assembling and connecting process satisfying the requirements of the sealing property of the combined structure is obtained. The nonlinear static finite element model of the key combination structure of the diesel engine is established. The influence of the different assembly connection technology on the sealing property of the cylinder of the diesel engine is studied, and the best cylinder head bolt assembling and connecting process which meets the requirements of the sealing property of the cylinder of the high-strength diesel engine is obtained. This paper provides the guidance for the modern design of the cylinder sealing property of the key parts of the high-strength diesel engine. 3) The combination structure of the bolt flange with the gasket and the gasket with different materials is put forward, and the response frequency and the vibration mode of the pre-stressed mode of the different combined structure are calculated. The accuracy of the modal simulation results is determined by comparing the modal test with the corresponding combination structure. The results show that the two bending mode frequencies of the composite structure are reduced by 13. 5% and 13. 7%, respectively, compared with the aluminum alloy gasket using the linear elastic material. the axial integral stiffness of the combined structure is found to have obvious pull-and-pressure non-linear characteristics, and the simplified equivalent of the bolt connection part of the combined structure is an axial double-spring-bending beam analysis model, and when the composite structure is not provided with a gasket or an aluminum alloy gasket with a wire elastic material is adopted, the axial tensile and pressing rigidity of the composite structure bolt is in a bilinear relation, and when the graphite of the non-linear material is used for winding the metal gasket, The axial tensile and compressive stiffness of the system presents a strong nonlinear relation. 5) The combined structure is simplified as a spring-mass system, and the vibration control equation of the system is established. under the action of transverse load, when the axial stiffness of the spring is constant or the stiffness is a displacement function of the displacement and the mass matrix of the vibration control equation is coupled, the combined structure only generates transverse angular vibration, When the axial stiffness of the spring is a displacement function and the mass matrix of the vibration control equation is not coupled, and the spring rate is a quadratic function of the linear and the stiffness as the displacement, the combined structure generates transverse and longitudinal coupling vibration. under the action of axial and lateral coupling impact, the combined structure also generates transverse and longitudinal coupling vibration. The simplified dynamic finite element model of the axial pull-and-pressure nonlinear stiffness of the bolt-flange gasket-connection composite structure is established, and the simplified dynamic model of the combined structure is calculated by the finite element simulation under the action of the axial and transverse loads respectively, and the axial and lateral vibration characteristics of the combined structure are obtained. The results show that the finite element calculation results of the simplified dynamic model and the analytical results of the mechanism model have good consistency. The transient dynamic impact test of the combined structure is designed, and the correctness of the proposed nonlinear simplified dynamic model and the mechanism analysis model of the combined structure is verified, and the theoretical prediction of the dynamic mechanism model is verified. The cylinder head bolt connection part of the key part combination structure of a high-strength diesel engine is re-modeled, and the axial stiffness non-linearity of the spring unit is taken into the integral dynamic analysis of the key component combination structure of the diesel engine, and the integral dynamic calculation of the key component combination structure of the diesel engine is carried out; For the first time, a large axial displacement of the combined structure under the axial impact is predicted, and the horizontal longitudinal coupling vibration is generated by the combined structure under the transverse impact, and the proposed nonlinear simplified dynamic modeling method is more safe and reliable.
【學(xué)位授予單位】：北京理工大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2015
【分類號】：TK421
本文編號：2404718
[Abstract]:The mechanical properties of the bolt-connecting composite structure become more complex due to the influence of the non-linearity of the gasket material and the non-linearity of the contact between the components of the combined structure. In order to study the overall mechanical properties of the composite structure, this paper studies the nonlinear static dynamic modeling method of the bolt flange gasket joint structure, the quasi-static sealing property and the dynamic response mechanism of the combined structure, and the specific research contents include: 1) Considering the non-linearity of the gasket material and the contact non-linearity between the components, the nonlinear static finite element model of the composite structure is established. The residual pre-tightening force of the bolt and the simulation result of the contact pressure of the gasket are obtained. compared with the test results, the correctness of the simulation calculation model and the calculation result is verified, and the optimal bolt assembling and connecting process satisfying the requirements of the sealing property of the combined structure is obtained. The nonlinear static finite element model of the key combination structure of the diesel engine is established. The influence of the different assembly connection technology on the sealing property of the cylinder of the diesel engine is studied, and the best cylinder head bolt assembling and connecting process which meets the requirements of the sealing property of the cylinder of the high-strength diesel engine is obtained. This paper provides the guidance for the modern design of the cylinder sealing property of the key parts of the high-strength diesel engine. 3) The combination structure of the bolt flange with the gasket and the gasket with different materials is put forward, and the response frequency and the vibration mode of the pre-stressed mode of the different combined structure are calculated. The accuracy of the modal simulation results is determined by comparing the modal test with the corresponding combination structure. The results show that the two bending mode frequencies of the composite structure are reduced by 13. 5% and 13. 7%, respectively, compared with the aluminum alloy gasket using the linear elastic material. the axial integral stiffness of the combined structure is found to have obvious pull-and-pressure non-linear characteristics, and the simplified equivalent of the bolt connection part of the combined structure is an axial double-spring-bending beam analysis model, and when the composite structure is not provided with a gasket or an aluminum alloy gasket with a wire elastic material is adopted, the axial tensile and pressing rigidity of the composite structure bolt is in a bilinear relation, and when the graphite of the non-linear material is used for winding the metal gasket, The axial tensile and compressive stiffness of the system presents a strong nonlinear relation. 5) The combined structure is simplified as a spring-mass system, and the vibration control equation of the system is established. under the action of transverse load, when the axial stiffness of the spring is constant or the stiffness is a displacement function of the displacement and the mass matrix of the vibration control equation is coupled, the combined structure only generates transverse angular vibration, When the axial stiffness of the spring is a displacement function and the mass matrix of the vibration control equation is not coupled, and the spring rate is a quadratic function of the linear and the stiffness as the displacement, the combined structure generates transverse and longitudinal coupling vibration. under the action of axial and lateral coupling impact, the combined structure also generates transverse and longitudinal coupling vibration. The simplified dynamic finite element model of the axial pull-and-pressure nonlinear stiffness of the bolt-flange gasket-connection composite structure is established, and the simplified dynamic model of the combined structure is calculated by the finite element simulation under the action of the axial and transverse loads respectively, and the axial and lateral vibration characteristics of the combined structure are obtained. The results show that the finite element calculation results of the simplified dynamic model and the analytical results of the mechanism model have good consistency. The transient dynamic impact test of the combined structure is designed, and the correctness of the proposed nonlinear simplified dynamic model and the mechanism analysis model of the combined structure is verified, and the theoretical prediction of the dynamic mechanism model is verified. The cylinder head bolt connection part of the key part combination structure of a high-strength diesel engine is re-modeled, and the axial stiffness non-linearity of the spring unit is taken into the integral dynamic analysis of the key component combination structure of the diesel engine, and the integral dynamic calculation of the key component combination structure of the diesel engine is carried out; For the first time, a large axial displacement of the combined structure under the axial impact is predicted, and the horizontal longitudinal coupling vibration is generated by the combined structure under the transverse impact, and the proposed nonlinear simplified dynamic modeling method is more safe and reliable.
【學(xué)位授予單位】：北京理工大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2015
【分類號】：TK421
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，本文編號：2404718
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