材料力学双语教学学习资料1主讲教师：陈晓峰第一章绪论Chapter1Introduction§1-1材料力学的任务TheTasksofMechanicsofMaterials1＊.材料力学:MechanicsofMaterials2.构件:StructuralMembers3.变形:Deformation4＊.强度:Strength5＊.刚度:Rigidity6＊.稳定性:Stability§1-2变形固体的基本假设FundamentalAssumptionsofSolidDeformationBodies1.连续性假设:Continuity2.均匀性假设:Homogeneity3.各向同性假设:Isotropy§1.3外力及其分类ExternalForcesandClassification1.分布力:DistributedForce2.集中力:PointForce3.静载荷:StaticLoad4.动载荷:DynamicLoad§1.4内力、截面法和应力的概念ConceptsofInternalForces，MethodofSectionandStress1＊.内力:InternalForce2＊.截面法:MethodofSection3.截面法的三个步骤：截开，代替，平衡Threestepsofmethodofsection:cutoff,substitute,andequilibrium.4＊.应力:Stress5.平均应力：Averagestress6.应力（全应力）：Wholestress（sumstress）7＊.正应力:NormalStress8＊.剪应力(切应力)：ShearingStress§1.5变形与应变DeformationandStrain1．线应变:Strain2．剪应变:ShearingStrain§1.6杆件变形的基本形式BasicTypesofDeformationsofRods1＊.拉伸或压缩:TensionorCompression2＊.剪切:Shear3＊.扭转:Torsion4＊.弯曲:Bending第二章拉伸、压缩与剪切Chapter2Tension，CompressionandShear§2.1轴向拉伸与压缩的概念和实例TheConceptandExamplesofAxialTensionandCompression1.拉杆:TensileRod2.压杆:CompressiveRod3.受力特点：外力合力的作用线与杆轴线重合CharacteristicoftheExternalForces:Theactinglineoftheresultantofexternalforcesiscoincidedwiththeaxisoftherod.4.变形特点：杆沿轴向伸长或缩短CharacteristicofDeformation:Rodwillelongateorcontractalongtheaxisoftherod.§2.2轴向拉伸或压缩时横截面上的内力和应力InternalForceandStressofAxialTensionorCompressionontheCrossSection1＊.横截面:CrossSection2＊.轴力:NormalForce3＊.轴力图:DiagramofNormalForce§2.3直杆轴向拉伸或压缩时斜截面上的应力StressofAxialTensionorCompressionontheSkewSection1.斜截面:SkewSection2.σα=σcos2ατα=σ2sin2α§2.4材料在拉伸时的力学性能MechanicalPropertiesofMaterialswithTensileLoad1.标准试件:Specimen2.低碳钢(C≤0.3%):LowCarbonSteel3.弹性阶段:ElasticRegion4.屈服阶段:YieldingStage5.强化阶段:HardeningStage6.颈缩阶段:NeckingStage7＊.σp----比例极限:ProportionalLimit8＊.σe----弹性极限:ElasticLimit9＊.σs----屈服极限:YieldingStress10＊.σb----强度极限:UltimateStress11.延伸率:PercentElongation12.断面收缩率:PercentReductionofArea13.塑性材料:DuctileMaterials14.脆性材料:BrittleMaterials15.铸铁:Castiron§2.7失效、安全系数和强度计算Failure,SafetyfactorandStrengthcalculation1＊.许用应力:AllowableStress2.安全系数:SafetyFactor3＊.强度条件:StrengthConditionσmax=FNA≤[σ]4＊.强度校核:Checkstrengthσmax≤[σ]5＊.截面设计:SectiondesignA≥FN[σ]6＊.确定许可载荷:DetermineallowableloadFN≤A[σ]§2.8轴向拉伸或压缩时的变形DeformationinAxialTensionorCompression1.弹性变形:ElasticDeformation2.塑性变形:PlasticDeformation3.纵向应变纵向应变::LongitudinalStrainε=Δll=l1−ll4.横向应变:LateralStrainε'=Δdd=d'−dd5．线弹性变形:LinearElasticDeformation6.泊松比::Poisson’sratioμ=|ε'ε|7＊.弹性模量-E：表示材料抵抗拉压变形的能力E-modulusofelasticity：Indicatesthecapabilityofmaterialsforresistingtensionorcompression8＊.抗拉刚度-EA:表示构件抵抗拉压变形的能力EA-theaxialrigidity:Indicatesthecapabilityofconstructivemembersforresistingtensionorcompression9＊.胡克定律（Hooke’sLaw）:当应力不超过材料的比例极限时，应力与应变成正比.Thestressisproportionaltothestrainwithintheelasticregion.σ=EεEALFLN§2.12应力...
