а) Для брусьев из пластичного материала, при равенстве по величине пределов текучести при растяжении и сжатии, наибольшие расчетные напряжения возникают в "опасных" точках, которые наиболее удалены от нейтральной оси.
Эти напряжения сравниваются с допускаемым напряжением :
после чего делается заключение о прочности бруса.
б) Если же брус изготовлен из хрупкого материала: , то в опасных сечениях наибольшие нормальные напряжения определяются и в растянутых, и в сжатых зонах поперечного сечения и путем сравнения их с соответствующими допускаемыми напряжениями при растяжении и сжатии :
Adventure holidays have become very important nowadays. In my opinion, adventure holiday is very interesting and exciting. On an adventure holiday people can do snowboarding or windsurfing.
I haven’t decided where to go this summer but if I was going on an adventure holiday in winter I would go snowboarding so the weather would be extremely important for me. Another important thing would be safety so I would choose the equipment carefully.
Extreme sports such as mountain biking, scuba diving and skydiving are very fascinating. The most dangerous of them, to my opinion, is scuba diving because there are a lot of sharks and sharp stones in the water. You can also run out of oxygen and die.
People take up extreme sports because doing them brightens their life and makes them feel happy. But doing extreme sports can cause serious accidents. To avoid them, people should be attentive and concentrated while doing extreme sports. They also should fasten their equipment correctly and follow all instructions that are given to them.
I’ve never participated in extreme sports but I’d like to go snowboarding very much. I’ve chosen this sport because it is good for my health and physical development.
а) Для брусьев из пластичного материала, при равенстве по величине пределов текучести при растяжении и сжатии, наибольшие расчетные напряжения возникают в "опасных" точках, которые наиболее удалены от нейтральной оси.
Эти напряжения сравниваются с допускаемым напряжением :
после чего делается заключение о прочности бруса.
б) Если же брус изготовлен из хрупкого материала: , то в опасных сечениях наибольшие нормальные напряжения определяются и в растянутых, и в сжатых зонах поперечного сечения и путем сравнения их с соответствующими допускаемыми напряжениями при растяжении и сжатии :
Объяснение:
I haven’t decided where to go this summer but if I was going on an adventure holiday in winter I would go snowboarding so the weather would be extremely important for me. Another important thing would be safety so I would choose the equipment carefully.
Extreme sports such as mountain biking, scuba diving and skydiving are very fascinating. The most dangerous of them, to my opinion, is scuba diving because there are a lot of sharks and sharp stones in the water. You can also run out of oxygen and die.
People take up extreme sports because doing them brightens their life and makes them feel happy. But doing extreme sports can cause serious accidents. To avoid them, people should be attentive and concentrated while doing extreme sports. They also should fasten their equipment correctly and follow all instructions that are given to them.
I’ve never participated in extreme sports but I’d like to go snowboarding very much. I’ve chosen this sport because it is good for my health and physical development.