No abstract

Ïðèâîäÿòñÿ ïîñòàíîâêà çàäà÷è è ðåçóëüòàòû ÷èñëåííûõ èññëåäîâàíèé ïðîñòðàíñòâåííîãî ïðîöåññà äèíàìè÷åñêîãî âçàèìîäåéñòâèÿ óäàðíèêà ñ òðóáîïðîâîäîì, ñîäåðaeàùèì aeèäêîñòü. Àíàëèçèðóþòñÿ ïðîöåññû òðàíñôîðìàöèè äâèaeåíèÿ óäàðíèêà, îáîëî÷êè òðóáîïðîâîäà è aeèäêîñòè â ïðîäîëüíóþ âîëíó ãèäðîóäàðà. Ïîêàçûâàþòñÿ îñîáåííîñòè âîëíîâûõ ïðîöåññîâ, ïðîèñõîäÿùèõ â òðóáîïðîâîäå, àíàëèçèðóþòñÿ íåîáðàòèìûå äåôîðìàöèè â ñòåíêå òðóáû, àìïëèòóäà è äëèòåëüíîñòü ïðîäîëüíîé âîëíû â aeèäêîñòè è â îáîëî÷êå òðóáû, âëèÿíèå êðàåâûõ óñëîâèé. Îöåíèâàåòñÿ ÷àñòü èìïóëüñà, ïðåîáðàçóþùàÿñÿ â ïðîäîëüíóþ âîëíó ãèäðîóäàðà.Êëþ÷åâûå ñëîâà: òðóáîïðîâîä, aeèäêîñòü, ãèäðîóïðóãîñòü, ïëàñòè÷íîñòü, äåôîðìàöèÿ, óäàð. ÂâåäåíèåÀêòóàëüíîñòü çàäà÷è îáóñëîâëåíà ïðèìåíåíèåì òðóáîïðîâîäîâ â ðàçëè÷íûõ ñôåðàõ äåÿòåëüíîñòè ÷åëîâåêà. Èññëåäîâàíèå ïðîöåññîâ äåôîðìàöèè òðóáîïðîâîäîâ ïðè óäàðíîì íàãðóaeåíèè îñîáåííî âàaeíî äëÿ òàêèõ îòðàñëåé ïðîèçâîäñòâà, êàê íåôòåãàçîâàÿ ïðîìûøëåííîñòü, àòîìíàÿ ýíåðãåòèêà è äð. Äëÿ îöåíêè ïîñëåäñòâèé âîçìîaeíûõ àâàðèéíûõ ñèòóàöèé íåîáõîäèìî èññëåäîâàòü ïðî÷íîñòü òðóá ïîä âîçäåéñòâèåì èìïóëüñíûõ íàãðóçîê. Áîëüøàÿ ÷àñòü èññëåäîâàíèé äèíàìèêè òðóáîïðîâîäîâ ñ çàïîëíÿþùåé aeèäêîñòüþ ïîñâÿùåíà òîðöåâîìó èìïóëüñíîìó íàãðóaeåíèþ è èçó÷åíèþ âîçíèêàþùåãî â íèõ ãèäðîóäàðà [1−3]. Ïðè èíòåíñèâíîì íàãðóaeåíèè íàáëþäàþòñÿ íåëèíåéíûå ýôôåêòû óïðóãîïëàñòè÷åñêîãî äåôîðìèðîâàíèÿ â òðóáîïðîâîäå è êàâèòàöèè â aeèäêîñòè. Íà òåìó óäàðíîãî íàãðóaeåíèÿ òðóáîïðîâîäîâ ìîaeíî íàéòè ðàáîòû, ðàíåå âûïîëíåííûå àâòîðàìè íàñòîÿùåé ñòàòüè [4−6].  ýòèõ ðàáîòàõ îïèñàíû èññëåäîâàíèÿ áîêîâîãî óäàðà ïî òðóáîïðîâîäó, çàïîëíåííîìó aeèä-ÏÐÎÁËÅÌÛ ÏÐÎ×ÍÎÑÒÈ È ÏËÀÑÒÈ×ÍÎÑÒÈ, ò. 77, ¹ 3, 2015 ã. * Âûïîëíåíî ïðè ÷àñòè÷íîì ôèíàíñèðîâàíèè ÐÔÔÈ (ãðàíòû ¹15-48-02333-ð_ïîâîë-aeüå_à, ¹13-08-00219, ¹14-08-00197, ¹14-08-31149-ìîë_à), Ïðîãðàììîé ãîñóäàðñòâåííîé ïîääåðaeêè âåäóùèõ íàó÷íûõ øêîë ÐÔ (ãðàíò ÍØ-593.2014.8) è ÐÍÔ (ãðàíò ¹14-19-01096) â ÷àñòè ïîñòàíîâêè òðåõìåðíîé çàäà÷è ãèäðîóïðóãîñòè.The formulation of the poblem and the results of numeically investigating the spatial process of a dynamic interaction between a striker and a pipeline carrying a liquid are presented. The processes of transformation of the motion of the strriker, the pipeline shell and the liquid into a longotudinal hydro shock wave are analyzed. The specific features of the wave processes in the pipeline are shown; deformations in the pipe wall, the amplitude and the length of the longitudinal wave in the liquid and in the pipe shell are analyzed, as well as the effect of the boundary conditions. The part of the pulse transforming into a longitudinal hydro shock wave is evaluated.

Simulation of elastoplastic compression of a symmetric fragment of a bundle of woven steel grids was carried out. The simulation was carried out under static and dynamic loading modes in ANSYS and ANSYS LS-DYNA computing systems. A porous mesh package is formed by overlaying the layers on top of each other while maintaining the directions of wires. Such a packet has a quasiperiodic structure; therefore, a certain symmetric fragment can be distinguished. The compression was carried out by a pair of absolutely rigid plates moving symmetrically towards each other. In the calculations, a multilinear plasticity model with isotropic hardening was used. The diagram of static deformation of the material was used which was obtained experimentally. The calculations were carried out according to the algorithm of a perfect symmetric contact of bodies without friction and with friction. The dynamic loading of a fragment of the mesh packet was carried out at a constant speed. The characteristics of the pulse and the loading rate correspond to those observed in previous experimental studies. The dynamic strain diagram was assumed to be similar to a static one with an increased yield strength. Calculations showed that in all loading modes there is a high level of internal stresses, and complex inhomogeneous stress-strain state. We investigated two factors that could cause differences in the behavior of the curves of deformation of a porous medium - the finite length of the acting pulse and the differences in the dynamic and static compression diagrams of the initial mesh material. The main influence on the dynamic behavior of a fragment of a porous packet of a steel mesh is exerted by the dynamic properties of the wire material. The strain curves of the porous fragment qualitatively change in accordance with the behavior observed in static and dynamic experiments. The final duration of the loading pulse and the friction between the wires for this type of mesh do not have a significant effect. The numerical dependences of the relative area of the normal and lateral through sections of the symmetric fragment of the grid packet on the compression deformation are obtained.

Ïîñòóïèëà â ðåäàêöèþ 15.12.2014 Ðàññìîòðåí ïîäõîä ê ïðîáëåìå èíòåðïîëÿöèè, âîçíèêàþùåé ïðè ðåøåíèè òåðìîïðî÷íîñòíîé çàäà÷è ñðåäñòâàìè ANSYS ñ ó÷åòîì ðàçëè÷èÿ ãåîìåòðèè ñåòî÷íûõ ìîäåëåé òåïëîâîé è ïðî÷íîñòíîé çàäà÷. Äëÿ ïåðåíîñà çíà÷åíèé ïîëÿ òåìïåðàòóð ñ òåïëîâîé ñåòêè íà ïðî÷íîñòíóþ ðàçðàáîòàí àëãîðèòì ïîëèëèíåéíîé èíòåðïîëÿöèè íà íåðàâíîìåðíûõ ñåòêàõ, ó÷èòûâàþùèé íåñîâïàäåíèå ðàñ÷åòíûõ îáëàñòåé òåïëîâîé è ïðî÷íîñòíîé çàäà÷ âáëèçè ãåîìåòðè-÷åñêèõ ãðàíèö. Ðåàëèçîâàí è ïðîòåñòèðîâàí ïðîãðàììíûé êîä, îñóùåñòâëÿþùèé êîððåêòíîå ðåøåíèå çàäà÷è èíòåðïîëÿöèè, ìèíèìèçèðóþùèé âðåìÿ ðàñ-÷åòà, àâòîìàòèçèðóþùèé îáìåí äàííûìè íà ðàçíûõ ýòàïàõ ðàñ÷åòà ñâÿçàííîé çàäà÷è.Êëþ÷åâûå ñëîâà: ñâÿçàííàÿ çàäà÷à, òåðìîñèëîâîå íàãðóaeåíèå, ìåòîä êî-íå÷íûõ ýëåìåíòîâ, èíòåðïîëÿöèÿ òåìïåðàòóðíîãî ïîëÿ.ÏÐÎÁËÅÌÛ ÏÐÎ×ÍÎÑÒÈ È ÏËÀÑÒÈ×ÍÎÑÒÈ, ò. 77, ¹ 2, 2015 ã.

Ïðèâîäÿòñÿ ðåçóëüòàòû ÷èñëåííîãî ìîäåëèðîâàíèÿ âîëíîâûõ ïðîöåññîâ ïðè íîðìàëüíîì óäàðå è ïðîíèêàíèè öèëèíäðîêîíè÷åñêîãî òåëà â îäíîðîäíûé ìÿãêèé ãðóíò â ìåðçëîì è íåìåðçëîì ñîñòîÿíèè. Ãðóíòû ìîäåëèðóþòñÿ ñaeèìàåìîé ñðåäîé Ñ.Ñ. Ãðèãîðÿíà ñ íåîáðàòèìûìè îáúåìíûìè è ñäâèãîâûìè äåôîðìàöèÿìè. Ðåçóëüòàòû ÷èñëåííûõ ðàñ÷åòîâ ñîïîñòàâëÿþòñÿ ñ èçâåñòíûìè ýêñïåðèìåíòàëüíûìè äàííûìè. Ïîêàçàíî, ÷òî ãëóáèíû ïðîíèêíîâåíèÿ â ìåðçëûé ãðóíò ïðè çíà÷èòåëüíîé îòðèöàòåëüíîé òåìïåðàòóðå áîëåå ÷åì â 6 ðàç íèaeå, ÷åì â íåìåðçëûé. Êëþ÷åâûå ñëîâà: óäàð, ïðîíèêàíèå, ìåðçëûé ãðóíò, ìàòåìàòè÷åñêîå ìîäåëèðîâàíèå, ñðàâíåíèå ñ ýêñïåðèìåíòîì.