熱應力紋裂 的英文怎麼說
中文拼音 [rèyīnglìwénliè]
熱應力紋裂
英文
thermal stress cracking-
This paper aims at the characteristics of thermal response of lpg vesse1 under high temperatue, conjoining the project of " study on transportation safety early - wdring system of lpg dangerous goods " supported by transportation departinen of china and the project of " mechanism study and numerical simulation of the explosion of lpg vessel " supported by science foundation of hubei province. the interdisciplinary research has been done among temperature field distribution of lpg vessel under flame surroundings, intensity calculation, crack propagation predication and mechanism of explosive accident, etc. three parts are analyzed and discussed
本文針對高溫環境下液化氣壓力容器的熱響應特性問題,結合交通部重點科技項目「液化氣體類危險品運輸安全預警系統的研究」和湖北省自然科學基金項目「液化氣容器爆炸機理研究及數值模擬」 ,對在火焰包圍下的液化氣壓力容器的溫度場分佈、強度計算、裂紋擴展預測以及爆炸事故機理等方面開展了多學科的交叉研究。The compatibility and harmony among workability, mechanical grade and durability are optimized, with the ground of adjusting composition and dosage of fd - 1 ; after analyzing anti - freezing damage mechanism, it is concluded that temperature is main factor, which affects structure and property of concrete. after two processes of temperature - elevation of hydration heat and temperature - descent of cold - environment, there is original damage in concrete and its existence leads to temperature fields, as results in temperature damage on transition phase > aggregate and cement mortar of concrete
通過對負溫混凝土早期防凍分析研究認為,環境溫度對混凝土的結構形成及其性能的影響十分突出,水泥水化溫升和環境散熱降溫兩個過程導致混凝土結構內部產生不均勻溫度場,對過渡相、水泥砂漿以及骨料都能產生不同程度的溫度損傷,產生內部溫差應力裂紋,初始損傷也是不可避免的。With the very low water to cement ratio, rpc has ultra - high strength high ductility and low permeability. in this paper, the compressive strength of rpc can reach to a high point with the number approximately 135mpa. as illustrated from the study results, we can approve some fundamental conclusions : there are big effects on rpc with deferent kinds and properties of raw materials and deferent curing conditions ; stress - strain curve shows the process of destroy with rpc samples ; x - ray diffraction analysis indicates that heat treatment at temperatures 90 accelerate the hydration of rpc sharply, therefore, mechanical and microstructural properties of rpc are highly dependent on heat treatment ; it is believed that rpc materials have excellent resistance to chloride permeability ; during the heat treatment, the shrinkage of rpc developed quickly because of chemical reactions ; the rpc with slag mostly has the advantage of rpc without slag about resistance to solutions corrosion
研究結果表明:通過對rpc各組分摻量變化的研究,可以找到rpc的最優配合比;試件成型后的熱養護制度對rpc的性能影響巨大; rpc的抗壓應力?應變曲線可以反映出試件受破壞時微裂紋的擴展情況,剛纖維的摻入可以大幅改善rpc的韌性; rpc在成型后存在較大的收縮,而其中的化學收縮要遠遠大於乾燥收縮; rpc具有很強的抗氯離子滲透性能,漿體的密實度很高;通過x射線衍射實驗,可以發現rpc的膠凝體中ch晶體已經幾乎不存在,膠凝體主要由c - s - h凝膠和未水化水泥顆粒組成;在抗溶液侵蝕的實驗中,摻礦渣rpc的抗溶液侵蝕性能在絕大多數情況下要好於不摻礦渣試件,酸、堿溶液和浙江工業大學碩士學位論文摘要一些鹽溶液都會對rpc的結構產生侵蝕作用,但是機理各有不同。Results show that the brittle fracture is mainly caused by hydrogen brittleness that results from the oxidation arid absorbing hydrogen of copper tube during braze welding
同時在加熱和冷卻時,由於異種材料的熱脹系數差別過大,產生的較大熱應力作用於已存在的裂紋,促使裂紋二次擴展,甚至使得晶粒脫落產生空洞,最終導致焊接接頭漏氣失效。According to these, the paper put forward some countermeasures : select low carbon steel or low metal alloy steel with lower intensity, like 20r steel ; while welding, adopt strict craft measures with lower welding heat to input ; after jointing, proceed the whole hot dissolving on time ; control each welding joint with hardness hb 185 ; add 0. 25 % water into the liquid ammonia as decay eclipse ; enhance checking in operation, repairing equipment in time through regular interior and exterior checking
針對上述原因提出了防止氨冷器類臨氨壓力容器產生應力腐蝕裂紋的對策:選用強度稍低,但抗裂性較好的低碳鋼和低合金鋼,如用20r鋼製造;焊接時應採用嚴格的工藝措施和較低的焊接熱輸入量;焊后應及時進行整體消除應力熱處理;控制焊接接頭各區硬度hb 185 ;在液氨中添加0 . 25 %的水作為緩蝕劑;在運行中加強檢查,及時進行停車檢修時的內外部檢查和定期檢驗。Abstract : the process of thermal fatigue crack propagation on the surface of steel bonded carbide gjw35 under the action of thermal stress has been observed
文摘:觀察了在熱應力作用下gjw35鋼結硬質合金表面熱疲勞裂紋擴展過程。The main work in this paper is as follows : in this paper, three - dimensional ( 3d ) finite element analyses were performed to obtain the j intensity value of crack repaired by bonded composite patch by considering the 3d stress state of patch crack
考慮到含裂紋結構修補技術是三維問題,本文建立了裂紋修補問題的三維有限元模型。通過對模型的靜力分析,計算了斷裂參數j積分,並對模型進行了熱-力耦合場的應力分析。The thermal fatigue resistance of al2o3 - 20wt. % tic is the best, it is due to high kic and pore of the material. the pore decrease the stress extension of tip of cracks and delay themal shock fatigue cracks extension. 4
含20wt . tic的復合陶瓷具有高的k _ ( 1c )和較多的孔隙,這些空隙在熱震疲勞時降低熱震疲勞裂紋尖端的應力集中並阻礙裂紋擴展從而提高了材料的斷裂抗力,故其具有最好的抗熱疲勞性能。In this thesis, in order to search the condition and reason of failure for a combustor, thermal stress was analyzed in steady and transient temperature field. according to the investigation, three conclusions are obtained
在忽略瞬態升溫過程得到的穩態溫度場作用下,火焰筒的熱應力不足以導致裂紋萌生,所以僅進行穩態分析不能得到合理的結論。Zhang liji ( material physics and chemistry ) directed by professor xie xiaoming this paper is intended to solve problems for those who are designing, using pbgas. failure mechanism, as well as cycles to failure of two groups of pbga samples ( with / without underfill ) for thermal cycling conditions in the range of - 40 ~ 125, were presented. the experiment shows that solder ball in the samples without underfill cracked after 500 times cycle, no crack was found in the underfilled samples even after 2700 cycles
通過一系列的實驗,得到以下實驗結果: ?在本論文設定的溫度循環條件下,未充膠pbga樣品的熱疲勞品壽命在500周左右,充膠樣品的焊點壽命高於2700周; ?對于未充膠器件,中心距( dnp )是決定焊點應力、應變大小的最主要因素,裂紋總是從中心距較大處萌生並向中心處擴展; ?溫度循環的過程中焊盤附近焊料組織明顯粗化。If there are high temperature gradient between cool liner and hot liner, compressive plastic strain appear at that transient time, which lead to gas film wall bearing high tensile stress at high temperature. high tensile stress is one of main reasons which destroy combustor
分析表明,起動過程中由於熱傳導滯后引發的溫度梯度可以導致火焰筒氣膜唇邊在起動瞬間發生較大的壓縮塑性應變,進而使得該區域在工作時承受較高水平的拉伸應力,高的拉應力會導致火焰筒萌生裂紋。The traction - free condition on the crack line is mended to get more accurate results. it can be expressed by a series of integral equations which can be discretized to a set of linear equations and then it can be solved easily. stress intensity factors ( sif ) are gotten through the root of the linear equations
( 2 )推導了遠場應力、熱應力耦合作用下含夾雜裂紋體的應力強度因子求解公式,改進了體積力法中的裂紋面合力平衡條件,將應力強度因子的求解歸結為解一組積分方程,再將積分方程轉化為線性方程組進行數值求解。At the same time, bem formulae for interface crack analysis of thermal barrier coated structures are given in this paper. the method to evaluate nearly - singular integrals over crack tip elements and the formulae for calculating stress intensity factors ( sif ) using open and slip displacements on crack faces are presented too
基於邊界元法、斷裂力學等基本理論,本文導出了帶熱障塗層構件界面裂紋的斷裂特性分析邊界元法公式;結合先進的近奇異積分技術處理裂尖元的近奇異積分,利用位移法計算層間界面裂紋的應力強度因子。The mechanism of physical damage of carbon fibers was clarified firstly. the precursor which attached on carbon fibers changes to inorganic ceramic under high temperature with large volume shrinkage which appearing at cracks with fiber traction and the cracks are mainly vertical to fiber axis. because of mismatched coefficients of thermal expansion, carbon fibers suffer multiple thermal stresses and are damaged
首次探明了碳纖維熱應力物理損傷機制,即碳纖維表面附著的先驅體在高溫下無機化形成陶瓷體,同時伴隨著大的體積收縮,在碳纖維的牽引下,基體的體積收縮以開裂形式出現,裂紋的取向以垂直於纖維軸向為主,由於碳纖維與基體熱膨脹系數失配,致使碳纖維在降溫過程中受到復雜熱應力,引起碳纖維損傷。分享友人