钢结构设计原理 刘智敏 第三章课后题答案.docx

第3章 钢结构的连接12. 如图3-57所示的对接焊缝，钢材为Q235，焊条为E43型，采用焊条电弧焊，焊缝质量为三级，施焊时加引弧板和引出板。已知，试求此连接能承受的最大荷载。解：因有引弧板和引出板，故焊缝计算长度lw=500mm，则焊缝正应力应满足：其中，故有，故此连接能承受的最大荷载为F=505.86kN。13. 图3-58所示为角钢214010构件的节点角焊鏠连接，构件重心至角钢肢背距离e1=38.2mm，钢材为Q235BF，采用手工焊，焊条为E43型，ffw=160N/mm2，构件承受静力荷载产生的轴心拉力设计值为N=1100kN，若采用三面围焊，试设计此焊缝连接。解:正面角焊缝且hf鈮?1.516=6mm故可取hf=8mm，此时焊缝的计算长度正面焊缝的作用：则由平衡条件得：所以它们的焊缝长度为，取370mm， ，取95mm。17. 如图3-61所示的焊接工字形梁在腹板上设一道拼接的对接焊缝，拼接处作用有弯矩，剪力V=374kN，钢材为Q235B钢，焊条用E43型，半自动焊，三级检验标准，试验算该焊缝的强度。解：（1）确定焊缝计算截面的几何特征x轴惯性矩：中性轴以上截面静矩：单个翼缘截面静矩：（2）验算焊缝强度焊缝最大拉应力（翼缘腹板交接处）：查表知，ftw=185N/mm216mm，故取f=205N/mm2。刚度满足要求。又，由其查表可得故整体稳定性满足要求。（2）采用热轧H型钢由于热轧H型钢可以选用宽翼缘的形式，截面宽度较大，因而长细比的假设值可适当减小，假设位=60，对宽翼缘截面h/b0.8，故构件的截面为类型均为b类。需要的截面几何量为：查表，试选。截面验算：因截面无孔削弱，可不验算强度；又因轧制H钢的翼缘和腹板均较厚，可不验算局部稳定，只需进行刚度和整体稳定验算。因其翼缘t=14mm0.8，故构件的截面为类型均为b类。需要的截面几何量为：按经验计算，工字形截面：根据以上参数，设计截面尺寸如右图所示。截面的几何特性为：ix=IxA=69.01脳10612520=74.2mmiy=IyA=50.7脳10612520=63.6mm截面验算：因截面无约束，可不验算强度。刚度和整体稳定验算：刚度满足要求又，由其查表可得故整体稳定性满足要求。局部整体稳定验算：故局部稳定满足要求。and out of the project within the control zone channel and status information for each room in the identification, recording, storing, querying, through the front controller, card reader . Access control systems and fire alarm systems can be either a network communication or serial interface communication, you can also use hard interface of linkage with the fire protection system. When a fire occurs, access control system to manage the host partition of the area displayed on the screen and alarm location, defining evacuation routes according to the preset program instructions, according to the location of the fire and emergency evacuation doors open or isolate the fire door closed. When more than one signal alarm, can be displayed according to a preset priority level to determine the order or arrangement of the screen. Access control system with map editing features, administrators can monitor the plane centered on the map design, can be divided according to their own requirements zone when when alarm events occur within a zone, the zone on the map system security will trigger linkage, and visually displayed on the map, and allow managers to quickly develop a treatment approach. Centre for consumer card (this system is included in the access control system) Center expends a cartoon system uses b/s and c/s architecture can be used with any management platform system interconnection. Mainly to meet internal and external canteen dining rate card, canteen and issuing data center real-time information sharing through databases. POS machine through TCP/IP communications way security, and efficient Active upload information to management server, system can according to itself consumpt