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第二章2.1 如图2-34所示钢材在单向拉伸状态下的应力－应变曲线，请写出弹性阶段和非弹性阶段的σε-关系式。
tgα'=E'f y 0f y 0tgα=E 图2-34 σε-图（a ）理想弹性－塑性（b ）理想弹性强化解：（1）弹性阶段：tan E σεαε==⋅非弹性阶段：y f σ=（应力不随应变的增大而变化） （2）弹性阶段：tan E σεαε==⋅ 非弹性阶段：'()tan '()tan y y y y f f f E f Eσεαεα=+-=+-2.2如图2-35所示的钢材在单向拉伸状态下的σε-曲线，试验时分别在A 、B 、C 卸载至零，则在三种情况下，卸载前应变ε、卸载后残余应变c ε及可恢复的弹性应变y ε各是多少？2235/y f N mm = 2270/c N mm σ= 0.025F ε= 522.0610/E N mm =⨯2'1000/E N mm =f yσF图2-35 理想化的σε-图解：（1）A 点：卸载前应变：52350.001142.0610y f Eε===⨯卸载后残余应变：0c ε=可恢复弹性应变：0.00114y c εεε=-=卸载前应变：0.025F εε== 卸载后残余应变：0.02386y c f Eεε=-=可恢复弹性应变：0.00114y c εεε=-=（3）C 点： 卸载前应变：0.0250.0350.06'c yF f E σεε-=-=+=卸载后残余应变：0.05869cc Eσεε=-=可恢复弹性应变：0.00131y c εεε=-=2.3试述钢材在单轴反复应力作用下，钢材的σε-曲线、钢材疲劳强度与反复应力大小和作用时间之间的关系。
答：钢材σε-曲线与反复应力大小和作用时间关系：当构件反复力y f σ≤时，即材料处于弹性阶段时，反复应力作用下钢材材性无变化，不存在残余变形，钢材σε-曲线基本无变化；当y f σ>时，即材料处于弹塑性阶段，反复应力会引起残余变形，但若加载－卸载连续进行，钢材σε-曲线也基本无变化；若加载－卸载具有一定时间间隔，会使钢材屈服点、极限强度提高，而塑性韧性降低（时效现象）。
钢结构设计原理课后习题答案 1. 请计算以下梁的截面模量：截面尺寸，宽度b=300mm，高度h=500mm，截面积A=150000mm²。
截面模量的计算公式为，S = bh²/6。
代入数据计算得，S = 300mm × (500mm)²/6 = 25,000,000mm³。
2. 请计算以下梁的弯矩：荷载，P=100kN。
距离，L=5m。
弯矩的计算公式为，M = PL。
代入数据计算得，M = 100kN × 5m = 500kNm。
3. 请计算以下梁的抗弯能力：截面模量，S=25,000,000mm³。
弯矩，M=500kNm。
抗弯能力的计算公式为，σ = M/S。
代入数据计算得，σ = 500kNm/25,000,000mm³ = 0.02N/mm²。
4. 请计算以下梁的剪力：荷载，P=50kN。
剪力的计算公式为，V = P。
代入数据计算得，V = 50kN。
5. 请计算以下梁的截面面积：截面尺寸，宽度b=400mm，高度h=600mm。
截面面积的计算公式为，A = bh。
代入数据计算得，A = 400mm × 600mm = 240,000mm²。
6. 请计算以下梁的抗剪能力：截面面积，A=240,000mm²。
剪力，V=50kN。
抗剪能力的计算公式为，τ = V/A。
代入数据计算得，τ = 50kN/240,000mm² = 0.000208N/mm²。
7. 请计算以下梁的轴心受压能力：截面面积，A=200,000mm²。
轴心受压能力的计算公式为，N = fA。
代入数据计算得，N = 0.6 × 200,000mm² = 120,000N。
8. 请计算以下梁的轴心受拉能力：截面面积，A=300,000mm²。
轴心受拉能力的计算公式为，N = fA。
钢结构设计原理课后答案
1. 钢结构设计的原理是基于力学原理，其中包括材料力学和结构力学。
2. 钢材的力学性能是进行钢结构设计的重要基础，包括材料的屈服强度、抗拉强度、弹性模量等。
3. 钢结构设计中的荷载分为静态荷载和动态荷载。
静态荷载包括自重、活载和附加荷载，动态荷载包括地震荷载和风荷载等。
4. 钢结构设计需要满足一系列的设计准则和规范，如国家标准和建筑行业规范等。
5. 钢结构设计过程中需要进行结构分析，包括静力分析和动力分析。
静力分析是通过计算结构的受力和变形情况，确定结构的安全性和稳定性。
动力分析则是针对地震和风荷载等动态荷载进行结构响应计算。
6. 钢结构设计中需要考虑结构的稳定性，包括整体稳定性和构件稳定性。
整体稳定性是指结构整体的稳定性，构件稳定性则是指结构中各个构件的抗侧稳定能力。
7. 钢结构设计中需要考虑结构的承载力，包括构件的强度和刚度。
强度是指结构抵抗外部荷载作用的能力，刚度是指结构抵抗变形的能力。
8. 钢结构设计中需要进行连接设计，包括连接的刚度和强度设
计。
连接的刚度设计需要保证连接的刚度和整个结构的刚度协调，连接的强度设计需要保证连接的强度不低于构件的强度。
9. 钢结构设计中需要考虑构件的施工性能，如可焊性、切割性、螺纹加工等。
施工性能对于结构的质量和施工进度有重要影响。
10. 钢结构设计中需要进行耐久性设计，保证结构在使用寿命
内具有良好的耐久性能，抵抗外界环境和腐蚀等因素的损害。
4. 1解:N = Y G N GK +Y Q N QK =1.2X |X 315 + 1.4X |X 315 = 420^焊缝质量为三级，用引弧板施焊。
查表得E43焊条的//= 185/V/mm 2,Q235 钢的 / = 215/V/mm 2。
N 420 X103 「北 t> ------ : ■ bf. = ---------- =1135mm 200x185 故取 f = 12mm o4. 2解:N = Y G N GK +Y Q N QK =1.2X O.2A/A +1.4X O.8A/A =l36N k 焊缝质量为二级，f t w =215N/mm 2未用引弧板施焊 l w — 400 — 2x12 = 316mmN = f ；v l w t = i.36N kf t w l w t. 1.36 = 215X376X12 亍山册1.364. 4解: 1）焊脚尺寸仰hf 、> 1 珀匚唤=l-5xV10 = 4.74mm h f[ < 1.2/inin = 1.2x8 = 9.6mm趾部尺寸! h /2 !-5At = 1.5x VlO = 4.74m/n WV^/2 "nin - （1 〜2）= 8-（1 〜2） = 6 〜7mm 为方便备料,取h f i = hf2 = hf = 6mm ,满足上述要求。
2） 轴心力N 的设计值N= Y C >N C .K ^Y Q N QK=1.2X 0」x 180 +1.4x 0.9x 180 = 248.4^按角钢背与趾部侧面角焊缝内力分配系数可知:等边角钢内力分配系 数 勺=0.3— = 0.7 bh对角钢趾部取力矩平衡得：N\b = N®N\=^N = 0.3N = 0.3x248.4 = 74.52RN 1 b N 2=N-N } =0.7^ =0.7X 24&4 = 173.88RN3） 焊缝长度。
7.1 一压弯构件长15m ，两端在截面两主轴方向均为铰接，承受轴心压力1000N kN =，中央截面有集中力150F kN =。
构件三分点处有两个平面外支承点（图7-21）。
钢材强度设计值为2310/N mm 。
按所给荷载，试设计截面尺寸（按工字形截面考虑）。
解：选定截面如下图示：图1 工字形截面尺寸下面进行截面验算：（1）截面特性计算()23002026502021420540A mm =⨯⨯+-⨯⨯=339411300650286610 1.45101212x I mm =⨯⨯-⨯⨯=⨯ 63/325 4.4810x x W I mm ==⨯337411220300610149.01101212y I mm =⨯⨯⨯+⨯⨯=⨯ 53/150 6.0110y y W I mm ==⨯266.2x i mm ==66.2y i m m = （2）截面强度验算36226100010562.510172.3/310/20540 4.4810x M N N mm f N mm A W σ⨯⨯=+=+=<=⨯ 满足。
（3）弯矩作用平面内稳定验算 长细比1500056.3266.2x λ== 按b 类构件查附表4-4，56.368.2，查得0.761x ϕ=。
2257222.061020540' 1.20101.1 1.156.3EX x EA N N ππλ⨯⨯⨯===⨯⋅⨯ 弯矩作用平面内无端弯矩但有一个跨中集中荷载作用：371000101.00.2 1.00.20.981.2010 1.1mx EX N N β⨯=-⨯=-⨯=⨯⨯， 取截面塑性发展系数 1.05x γ= 363611000100.98562.5100.7612054010001010.8 1.05 4.481010.8' 1.2010mx x x x x EX M N A N W N βϕγ⨯⨯⨯+=+⨯⎛⎫⎛⎫⨯-⨯⨯⨯-⨯ ⎪ ⎪ ⎪⨯⎝⎭⎝⎭ 22189.54/310/N mm f N mm =<= ，满足。
钢结构原理与设计课后答案1. What are the advantages of steel structures?Steel structures have several advantages over other construction materials, including:- High strength: Steel has a high strength-to-weight ratio, which means it can withstand heavy loads without being excessively bulky or thick. This allows for more efficient use of space and materials.- Durability: Steel is highly durable and has a long service life. It is resistant to corrosion, fire, and various environmental factors, making it suitable for a wide range of applications.- Flexibility: Steel structures can be easily modified, expanded, or reconfigured to meet changing needs. This flexibility allows for future adaptability and reduces the need for costly renovations or rebuilding.- Speed of construction: Steel structures can be fabricated off-site and assembled quickly on-site, reducing construction time significantly. This can lead to cost savings and faster project completion.- Sustainability: Steel is a highly sustainable material as it is recyclable and can be reused multiple times without losing its properties. Additionally, the use of steel structures can contribute to energy efficiency through integration with other sustainable technologies like solar panels.- Cost-effectiveness: Although steel structures may have higher upfront costs compared to other materials, their long-term benefits in terms of durability, maintenance, and adaptability often make them more cost-effective over the project's lifespan.2. How can steel structures be designed to resist lateral loads? Steel structures can be designed to resist lateral loads through several measures, including:- Bracing: The use of braces, such as cross-bracing or diagonal bracing, can provide stability and resistance against lateral forces. Bracing systems are typically located in the plane of the structure's walls or floors and help transfer the loads to the foundation.- Shear walls: Shear walls are vertical elements that provide resistance against lateral forces. These walls are designed to have high stiffness and strength and are typically placed at the perimeter of the structure or within the interior to create a rigid frame.- Moment-resisting frames: Moment-resisting frames are structural systems designed to resist lateral loads through moment transfer. These frames are typically used in buildings with open floor plans and consist of beams and columns that are capable of flexing under lateral loads.- Damping systems: Damping systems, such as tuned mass dampers or fluid viscous dampers, can be incorporated into steel structures to reduce the effects of lateral forces. These systems dissipate energy and help dampen vibrations caused by earthquakes or wind loads.- Base isolation: Base isolation involves installing flexible materials or bearings between the structure and its foundation to decouple them. This helps absorb and dissipate the energy generated by lateral loads, reducing their impact on the structure.3. What are the design considerations for steel structures in seismiczones?When designing steel structures in seismic zones, several considerations need to be taken into account:- Seismic load analysis: A seismic load analysis must be performed to determine the magnitude and direction of the potential seismic forces that the structure may experience. This analysis considers factors such as the seismic zone, site conditions, and the structure's response characteristics.- Strength and ductility: The design must account for the structure's strength and ductility to ensure that it can withstand the seismic forces without collapsing. Ductility allows the structure to undergo controlled deformations without significant loss of its load-carrying capacity.- Connection design: The connections between structural elements, such as beams and columns, must be designed to have adequate strength and ductility to accommodate the expected seismic forces. Proper detailing of connections is crucial to ensure load transfer and prevent failures during earthquakes.- Redundancy: Redundancy is the provision of multiple load paths within the structure. This ensures that even if one part of the structure fails, the overall integrity is maintained. Redundancy enhances the structure's resilience against seismic forces.- Seismic isolation or energy dissipation: Incorporating seismic isolation or energy dissipation systems can help reduce the impact of seismic forces. These systems are designed to absorb and dissipate energy, thereby protecting the structure from excessive deformations and damage.- Compliance with building codes: Designing steel structures inseismic zones requires compliance with the relevant building codes and seismic design regulations. These codes establish minimum requirements for structural integrity, safety, and performance during seismic events.4. How can steel structures be designed to resist fire?To design steel structures to resist fire, the following considerations need to be made:- Fire-resistant materials: Fire-resistant materials, such as fire-resistant coatings or insulation, can be applied to the steel members to protect them from high temperatures. These materials can delay or prevent the onset of structural failure and maintain the integrity of the steel structure during a fire.- Fire-resistant design: The dimensions and configuration of the steel members should be designed to minimize the potential for failure in case of fire. Adequate strength, stiffness, and fire resistance must be ensured through appropriate section sizes and reinforcement.- Compartmentalization: Building compartments with fire-resistant walls and floors can help contain the spread of fire and limit its impact on the steel structure. These compartments can prevent the fire from reaching critical structural components.- Active fire protection systems: Active fire protection systems, such as sprinklers, fire alarms, and smoke detectors, should be incorporated into the steel structure's design to help detect and suppress fires. These systems can help minimize fire damage and protect occupants.- Adequate egress routes: Proper provision of fire exits and clearevacuation routes should be incorporated into the design to ensure the safe evacuation of occupants in case of fire. These routes should be designed to minimize the risk of structural collapse during emergencies.- Compliance with fire codes and regulations: Steel structures should be designed in compliance with fire codes and regulations, which provide guidelines for fire-resistant materials, evacuation requirements, fire protection systems, and overall safety standards.5. What are the common methods used for steel connection design?Steel connection design involves determining the types and configurations of connections between various steel members. The common methods used for steel connection design include:- Welded connections: Welded connections are created by joining steel members together through the melting and fusion of the steel surfaces. Various types of welds, such as fillet welds or groove welds, can be used depending on the specific requirements and load conditions. Welded connections offer high strength but may require careful detailing for stress concentration and distortion control.- Bolted connections: Bolted connections use bolts to join steel members together. The bolts, along with nuts and washers, provide the clamping force necessary to hold the members in place. Bolted connections are versatile, as they allow for easy disassembly and reassembly. They can be designed as either bearing-type connections or slip-critical connections, depending on the required load transfer mechanism.- Riveted connections: Riveted connections involve using rivets,which are permanent mechanical fasteners, to join steel members. Rivets are inserted into pre-drilled holes and then heated, causing them to expand and secure the connection. Riveted connections were commonly used in the past but have been largely replaced by welded or bolted connections due to ease of fabrication and inspection.- Moment connections: Moment connections are designed to transfer bending moments between steel members, such as beams and columns. These connections allow the transfer of forces without relying solely on shear or axial load resistance. Moment connections increase the overall structural rigidity and can provide continuous load paths, enhancing the structure's resistance to lateral loads.- Splice connections: Splice connections are used to join steel members of the same type, typically to achieve longer spans or accommodate transportation and erection constraints. These connections can be designed as bolted or welded connections, depending on the desired level of stiffness and ease of assembly. Note: The above answers are provided for reference purposes and should be used as a guideline. It is important to consult relevant textbooks, materials, and experts for accurate and comprehensive information on steel structure principles and design.。
钢结构基本原理（第二版）习题参考解答第二章第二章钢结构的基本材料和构件习题参考解答1. 钢材的基本性能指标有哪些？请简要描述各项性能指标的含义。
答：钢材的基本性能指标包括强度、韧性、可塑性和耐腐蚀性。
- 强度：钢材的强度是指钢材抵抗外力的能力，通常以屈服强度、抗拉强度和抗压强度来表示。
屈服强度是指钢材在受到外力作用时，开始产生塑性变形的应力值；抗拉强度是指钢材在拉伸状态下最大的抵抗外力的应力值；抗压强度是指钢材在受到压缩状态下最大的抵抗外力的应力值。
强度的高低决定了钢材的承载能力。
- 韧性：钢材的韧性是指钢材在受到外力作用时，能够发生塑性变形而不断延展的能力。
韧性的好坏决定了钢结构在受到冲击或震动时的抵抗能力。
- 可塑性：钢材的可塑性是指钢材在受到外力作用时，能够发生塑性变形而不断延展的能力。
可塑性的好坏决定了钢材的加工性能和成型性能。
- 耐腐蚀性：钢材的耐腐蚀性是指钢材在受到各种腐蚀介质（如大气、水、酸等）的侵蚀时，能够保持其力学性能和表面的完整性。
耐腐蚀性的好坏决定了钢结构的使用寿命。
2. 钢材的分类方法有哪些？请简要描述各种分类方法。
答：钢材的分类方法有按化学成分分类、按用途分类和按加工方法分类。
- 按化学成分分类：钢材按化学成分可分为碳素钢、合金钢和不锈钢。
碳素钢的主要成分是碳和铁，其含碳量通常在0.08%~2.11%之间；合金钢是在碳素钢中添加其他合金元素（如铬、钼、锰等）来改善钢材的性能；不锈钢是指含有至少12%的铬元素，在大气或酸性介质中形成一层致密的氧化铬膜，起到防腐蚀的作用。
- 按用途分类：钢材按用途可分为结构钢、机械钢、特种钢和工具钢等。
结构钢是用于制造各种钢结构的钢材，如建筑、桥梁、船舶等；机械钢是用于制造机械零部件的钢材，如轴承、齿轮、轴等；特种钢是用于特殊工作条件下的钢材，如高温、低温、高压等环境下的钢材；工具钢是用于制造各种切削工具和模具的钢材，如刀具、冲压模具等。
- 按加工方法分类：钢材按加工方法可分为热轧钢材、冷轧钢材和锻制钢材。
钢结构第二版课后习题答案【篇一：钢结构基础(第二版)课后习题第四章答案】q235钢，翼缘为火焰切割边，沿两个主轴平面的支撑条件及截面尺寸如图所示。
已知构件承受的轴心压力为n=1500kn。
l?4m解：由支承条件可知l0x?12m，0y11?500?12?64ix??8?5003??250?123?2?250?12476.6?10 mm12122?? 50031iy??8?2??12?2503?31.3?106mm412122a?2?250?12?500?8?10000mmix??21.8cmiy5.6cm，l0y400l0x120071.4?x?55?y?i5.6ix21.8y，，2翼缘为火焰切割边的焊接工字钢对两个主轴均为b类截面，故按y查表得?=0.747n1500?103200.8mpa?f?215mpa整体稳定验算：?a0.747?10000，稳定性满足要求。
4.13图示一轴心受压缀条柱，两端铰接，柱高为7m。
承受轴心力设计荷载值n=1300kn，钢材为q235。
已知截面采用2[28a，单个槽钢的几何性质：a=40cm2，iy=10.9cm，ix1=2.33cm，解：柱为两端铰接，因此柱绕x、y轴的计算长度为：l0x?l0y?7m22b26??ix?2?ix1?a??y02?218?40??2.19940.8cm422l0y700l0x70064.263.1ix???11.1cmyxiy10.9ix11.10x格构柱截面对两轴均为b类截面，按长细比较大者验算整体稳定既可。
由?0x?65.1，b类截面，查附表得??0.779，65.1n1300?103208.6mpa?f?215mpa2整体稳定验算：?a0.779?2?40?10 所以该轴心受压的格构柱整体稳定性满足要求。
4.17焊接简支工字形梁如图所示，跨度为12m，跨中6m处梁上翼缘有简支侧向支撑，材料为q345钢。
集中荷载设计值为p=330kn，间接动力荷载，验算该梁的整体稳定是否满足要求。
4.1解：kN N N N QK Q GK G 420315324.1315312.1=⨯⨯+⨯⨯=+=γγ焊缝质量为三级，用引弧板施焊。
查表得E43焊条的2/185mm N f W t =，Q235钢的2/215mm N f =。
mm bf N t W t 35.11185200104203=⨯⨯=≥ 故取mm t 12=。
4.2解：k k k QK Q GK G N N N N N N 36.18.04.12.02.1=⨯+⨯=+=γγ焊缝质量为二级，2/215mm N f W t =未用引弧板施焊mm l W 376122400=⨯-= tl Nf W W t =，k W W t N t l f N 36.1== kN t l f N W W t k 3.71336.11237621536.1=⨯⨯==4.4解： 1）焊脚尺寸f h背部尺寸⎪⎩⎪⎨⎧=⨯=≤=⨯=≥mmt h mmt h f f 6.982.12.174.4105.15.1min 1max 1趾部尺寸()()⎪⎩⎪⎨⎧=-=-≤=⨯=≥mmt h mmt h f f 7~62~182~174.4105.15.1min 2max 2 为方便备料，取mm h h h f f f 621===，满足上述要求。
2）轴心力N 的设计值kN N N N QK Q GK G 4.2481809.04.11801.02.1=⨯⨯+⨯⨯=+=γγ按角钢背与趾部侧面角焊缝内力分配系数可知:等边角钢内力分配系数3.01=b e 7.02=be对角钢趾部取力矩平衡得: 21Ne b N =kN N N be N 52.744.2483.03.021=⨯===kN N N N N 88.1734.2487.07.012=⨯==-=3)焊缝长度。
当构件截面为一只角钢时，考虑角钢与节点板单面连接所引起的偏心影响， W t f 应乘以折减系数0.85。
角钢趾：mm h mm f h N l f W f f W 48813016085.067.01052.7485.07.0311=>=⨯⨯⨯⨯=⋅≥取mm l 1401= （mm h f 1422130=+，取10mm 的整数倍）角钢背：mm h mm f h N l f Wf f W 3606030416085.067.01088.17385.07.0322=<=⨯⨯⨯⨯=⋅≥ 取mm l 3202= （mm h f 3162304=+，取10mm 的整数）4.5解：腹板受到轴心拉力k N 作用kN N N N QK Q GK G 4.5984408.04.14402.02.1=⨯⨯+⨯⨯=+=γγ焊脚尺寸f hmmt h f 6.55.1max =≥，mmt h f 9~8)2~1(min =-≤取mm h f 6=时，mm h mm f h N l f Wf f W 360602.44516067.02104.5987.023=>=⨯⨯⨯⨯=⨯≥ 不可行；取mm h f 7=时，mm l w 6.381≥，mm h l f w 42060=≤ 可行，mm h l f 6.39526.381=+=，取mm l 400= 取mm h f 9=时，mm l w 8.296≥，mm h l f w 54060=< 可行，mm h l f 8.31428.296=+=，取mm l 320=故最小的焊脚尺寸可取mm 7，钢板搭接长度为mm 400 最大的焊脚尺寸可取mm 9，钢板搭接长度为mm 3204.7解：（1）直接计算法m kN Nl M ⋅=⨯==102.0502262/1.148862407.0101067.0mm N h h l h M ff W f f =⨯⨯==σ23/6.2972407.010507.0mm N h h l h N ff W f f =⨯⨯==τW f f f f f ≤+⎪⎪⎭⎫⎝⎛22τβσ 1606.29722.11.148822≤⎪⎪⎭⎫ ⎝⎛+⎪⎪⎭⎫ ⎝⎛f f h h 解得：mm h f 85.7= 采用()mmt mmt mmh f 9~82~136.6185.15.18min max =-≤=⨯=≥=，可（2）试算法()⎩⎨⎧=-≤=⨯=≥mmt mmt h f 9~82~136.6185.15.1min max 取mm h f 8=2134424087.07.0mm l h l h A W f W e W =⨯⨯=== 3225376024087.06161mm l h W W e W =⨯⨯⨯==2262/0.186624087.0101067.0mm N l h M W f f =⨯⨯⨯==σ 23/2.3724087.010507.0mm N l h N W f f =⨯⨯⨯==τ222222/160/9.1562.3722.1186mm N f mm N W f f f f =≤=+⎪⎭⎫ ⎝⎛=+⎪⎪⎭⎫ ⎝⎛τβσ，可 故mm h f 8=4.8解：kN R R R k k 405%754.1%252.1=⨯+⨯= mm l 300= mm l h 701080=-=取焊脚尺寸mm h f 6= mm h h f e 2.47.0== （1）几何关系水平焊缝计算长度mm h l l f h W h 64670=-=-= 全部焊缝计算长度mm l l l W h W 4286423002=⨯+=+= 全部焊缝有效截面W e W l h A = 形心位置cm h h A l l h x e e WWhWh e 96.08.4224.64.6222=⨯⨯⨯⨯=⋅=略去3e h 项423236.21542304.642.02123042.02212cm l l h l h I W h e e x =⎥⎥⎦⎤⎢⎢⎣⎡⎪⎭⎫ ⎝⎛⨯⨯⨯+⨯=⎥⎥⎦⎤⎢⎢⎣⎡⎪⎭⎫ ⎝⎛⋅+=42232238.4796.04.642.096.024.64.642.0124.642.022122cm x l h x l l h l h I W h e W hW h e W h e y =⨯⨯+⎥⎥⎦⎤⎢⎢⎣⎡⎪⎭⎫ ⎝⎛-⨯⨯+⨯⨯=+⎥⎥⎦⎤⎢⎢⎣⎡⎪⎭⎫ ⎝⎛-+= 焊缝有效截面对形心O 的极惯性矩404.22028.476.2154cm I I I y x =+=+=（2）强度验算kN R V 5.2022== mm x a 4.7080=-= m kN Ra T ⋅=⨯⨯==-3.142104.7040523mm x l x W h 4.546.9641=-=-= mm ly 15021==↑=⨯⨯⨯==24601/3.35104.22024.54103.14mm N I Tx Tfσ ←=⨯⨯⨯==2461/4.97104.2202150103.14mm N I Ty T fτ↑=⨯⨯==23/7.1124282.4105.202mm N A V V fσ剪力和扭矩共同作用下的强度条件()222222/160/6.1554.9722.17.1123.35mmN f mm N W f Tf f Vf Tf =≤=+⎪⎭⎫ ⎝⎛+=+⎪⎪⎭⎫⎝⎛+τβσσ，可5.1解：QK Q GK G N N N γγ+=则：N N k 8.772560%904.1560%102.1=⨯⨯+⨯⨯=查表，得：钢板螺栓孔壁承压承载力设计值：2/405mm N f b c = 螺栓的强度设计值为：2/190mm N f b v =)(32.1191019044002432kN f d n N bv e vbv =⨯⨯⨯⨯==-ππ)(1621040520203kN tf d N bc b c =⨯⨯⨯=∑=-取)(32.119},min{kN N N N b c b v b == 需要的螺栓数目：48.632.1198.772===b N N n 最少采用7=n试取螺栓距mm mm d p o 655.613≈== 端距mm mm d a o 45412≈== 边距mm mm d c o 3575.305.1≈==因为板宽mm b 250=，若边距为mm 35则不满足间距不大于mm t 12012=要求，故最外排每列螺栓应设3个，取螺栓横向间距为mm 90，端距为mm 45，螺栓数增加为8个。
取螺栓纵向间距为mm 65，边距为mm 35。
第二列布置2个螺栓，符合不大于mm t 24024=的构造要求。
已知，在最外侧螺栓处的截面，钢板受力最大，截面上有3个螺栓孔，其净面积为最小，即：21377020)5.203250()3(mm t d b A o n =⨯⨯-=-=净截面平均拉应力为：2231/205/2053770108.772mm N f mm N A N n =≤=⨯==σ，（1n A 为mm 20钢板面积，f 应该按照mm 20钢板取）可下面再验算拼接板四角处有无块状拉剪破坏的危险。
则每一块板呗抗剪破坏所需之力为)(9.2071021510)5.205.035(1012510)5.205.265245(331kN N =⨯⨯⨯⨯-+⨯⨯⨯⨯-⨯+=--拼缝一侧上、下两块拼接板同时有4角拉剪破坏时所需轴向力为)(8.772)(6.8319.207441kN kN N N >=⨯==因而此处不会发生块状拉剪破坏。
5.4解：2/190mm N f b v = 2/405mm N f b c =设螺栓单列为n 个。
kN P P P k k 544%804.1%202.1=⨯+⨯= m kN Pe T ⋅=⨯⨯==682505442121 （1）单个螺栓受剪承载力设计值： 螺栓杆被剪断承载力：kN f d n N b v vb v 2.721902241422=⨯⨯⨯==ππ螺栓孔承压破坏承载力：kN f t d N b b 56.1424051622=⨯⨯==∑c v min（2）求每列螺栓的个数n 的值。
取bT N N min =由修正公式（5.10）：83.535.6135.670102.722106861636=⎪⎭⎫ ⎝⎛-⨯⨯⨯⨯⨯=⎪⎭⎫ ⎝⎛-=n n p mN T n T取n=6（3）强度验算：螺栓除受扭转作用外，还受到竖向的剪力。
()kN y x Ty N i i i T xi93.47175105354801217510682222622=++⨯+⨯⨯⨯=+=∑∑ ()kN y x Tx N ii i Tyi91.2117510535480128010682222622=+++⨯⨯⨯=+=∑∑ kN nPN P y 67.222==由偏心剪力作用下强度条件：()()()kN N N NN bP yT yi T xi2.7246.6567.2291.2193.47min 2222=≤=++=++，可5.5解：2/140mm N f b v = 2/170mm N f b t = 2/305mm N f b c =设螺栓单列为n 个。
