GB/T 30024-2020 in English

《GB/T 30024-2020起重机 金属结构能力验证》由TC227（全国起重机械标准化技术委员会）归口，主管部门为中国机械工业联合会。

Foreword
This standard is drafted in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 30024-2013 "crane metal structure capability verification", compared with GB/T 30024-2013, the main technical changes are as follows.
Modified the normative references (see Chapter 2, Chapter 2 of the 2013 version).
Modified some of the main symbols used in this standard (see Chapter 3, Table 1, Chapter 3, Table 1 of the 2013 edition); a modification of the plane state stress of the weld link additional verification formula, that is, the coefficient on the right side of the equal sign from 1.1 to 1.0 [see equation (32), equation (32) of the 2013 edition 7.
Added elastic stability verification (see Chapter 7).
This standard uses the translation method equivalent to ISO 203322016 "crane metal structure capability verification" and the normative references in this standard international documents have consistent correspondence with our country's documents are as follows: GB/T 229-2007 Charpy pendulum impact test method for metal materials (ISO 148-1.2006, MOD) - GB/T 1800.2-2020 Product geometric specifications (GPS) linear dimensional tolerances ISO code system part 2: standard tolerance zone code and hole, shaft limit deviation table (ISO 286-2:2010, MOD)-GB/T 3098.1 a 2010 fastener mechanical properties of bolts, screws and studs (ISO898-1:2009, MOD) check fragrance hydrogen embrittlement with preload test parallel Support surface method (idt-GB/T 3098.17-2000 fastener mechanical properties ISO15330:1999)
GB/T 5267.1-2002 fastener plating layer (ISO4042:1999,IDT)
GB/T 15706---2012 General principles of mechanical safety design risk assessment and risk reduction (ISO 12100.2010.IDT)
GB/T 17505-2016 Steel and steel products GB/T 19349-2012 Pretreatment of steel with metal and other inorganic coverings to reduce the risk of hydrogen embrittlement (ISO 9587:2007, IDT)
GB/T 19418-2003 Guidelines for grading the quality of defects in arc-welded joints of steel (ISO 5817:1992, IDT) GB/T 20863.1-2007 Classification of cranes Part 1: General provisions (ISO 4301-1:1986, IDT) GB/T 22437 (all parts) Design principles for crane loads and load combinations Plant ISO 8686 (all parts) 7 This standard is proposed by the China Machinery Industry Federation.
This standard is attributed by the National Crane Standardization Technical Committee (SAC/TC227).

1 Scope
This standard is based on the limit state method specifies the general conditions, requirements, methods and parameter values determined by the crane metal structure for capacity verification to be used in concert with the applicable parts of the load and load combination in ISO 8686.
This standard is general in nature, applicable to all types of cranes. For dedicated special cranes, other standards can be specified by the specific requirements of its ability to verify.
Capability verification through theoretical verification calculations and/or testing is intended to avoid the hazards associated with structural performance with the established strength limits (e.g. yield limit, fatigue, brittle fracture).
According to ISO 8686-1, two methods can be used for capacity verification calculations: the limit state method with a sub-factor of safety, and the allowable stress method with an overall factor of safety. Although the validity of the permissible stress method is not excluded, but this standard only covers the limit state method.
This standard does not include the ability to verify the calculation of accessory parts (such as railings, stairs, walkways, driver's cab). However, it is necessary to consider the influence of these auxiliary parts on the main structure.
2 normative reference documents
The following documents are essential for the application of this document. Where the date of the referenced documents, only the date of the version applicable to this document.
GB/T6974.1-2008 crane terminology Part 1: General terminology (ISO4306-1:2007, IDT)
ISO148-1:2009 Charpy pendulum test of metal materials Part 1: Test methods
ISO273:1979 Fasteners screw and screw with through holes
ISO286-2.2010 Product geometry specifications (GPS)
ISO 404 General technical requirements for the delivery of steel and steel products
ISO 898-1:2013 Mechanical properties of fasteners made of carbon and alloy steels Part 1: Bolts, screws and studs with specified performance class coarse threads and fine pitch threads
ISO 4042 Fastener plating

3 terms, definitions, symbols and abbreviations
GB/T6974.1-2008 in Chapter 8, S12100 and SO17659 defined and the following terms, definitions, symbols and abbreviations (see Table 1) apply to this document.
3.1
Grade of steel gradeofsteel
The strength of steel (usually yield stress f, sometimes ultimate strength f,) is used to define the designation.
32
qualityofsteel
The markings defined by the impact toughness and test temperature of the steel are used.

4 Overview
4.1 General principles
Under load or repeated load cycles, capacity verification calculations should be performed for members, bars and details that may fail, break or deform and affect the function of the crane.
Note: For more information on verification calculations applicable to various types of cranes, please refer to SO8686. not all calculations are applicable to every type of crane.
4.2 Documentation
5 Static strength verification
5.1 Overview
The purpose of static strength verification by calculation is to prevent excessive deformation due to material yielding, slippage of clamping friction connections, elastic instability (see chapter 7) and fracture of structural members or connections. The dynamic effects can be simulated by calculating equivalent static loads using dynamic load factors given in the relevant part of ISO 8686 or in the product standards implemented according to ISO 8686-1.
This standard does not accept the use of plasticity theory to calculate the ultimate load carrying capacity.
Verification of structural members and connections shall simultaneously consider the most unfavorable load effects in the applicable part of SO8686 load combinations A, B or C
and compared with the ultimate design resistance given in 5.2. This standard considers only nominal stresses, i.e., stresses calculated using conventional material elastic strength theory, and does not include local stress concentration effects. Since the given limit states will be used together with the nominal stresses, if the stresses obtained using other stress calculation methods (e.g. finite element analysis) are used directly for the verification specified in this standard, it may produce overly conservative results.

6 Fatigue Strength Verification
6.1 Overview
The purpose of fatigue strength verification is to prevent the risk of failure by the formation of critical cracks in structural components or connections under cyclic loading.
Fatigue stresses are calculated based on the concept of nominal stresses. Only the nominal stress method is covered by this standard (see references for other methods). The nominal stress is the stress in the base material near the location of the potential crack, calculated according to the pure elastic strength theory of the material, without taking into account local stress concentration effects. Appendix D gives details of the construction of the structure containing illustrations of the effects and includes the following effects that affect the characteristic fatigue strength values.
Local stress concentrations caused by joint and weld geometry.
Size and shape of acceptable interruption points.
stress direction.
Residual stresses.
Smelting conditions.
In some cases, welding processes and post-weld improvement procedures.
In addition to the geometric stress concentration effects listed above (overall stress concentration), other geometric stress concentration effects should be included in the nominal stresses with the aid of the relevant stress concentration factors.

7 Sexual stability verification
7.1 Overview
Elastic stability verification is to ensure that an ideal linear structural member or component does not lose its stability due to transverse deformation caused by compressive or compressive stresses alone. Deformation caused by the combined action of compressive or compressive forces and out-of-plane bending or bending moments due to initial geometric defects in the structure should be assessed using second-order theory as part of the verification of static strength. This chapter covers the overall buckling of members under compression and the local buckling of thin plates under compressive stresses.
Note:Elastic instability exists or may also occur, for example in cylindrical shells or open sections. For detailed information, see Ref.
7.2 Lateral buckling of compressed members
7.2.1 Critical buckling load
According to the elastic theory, the buckling load N, is the minimum branch load. For equal-section members, Nk is determined according to Eulerian buckling state boundary conditions Table 12.

Appendix A (informative appendix) Ultimate design shear for each bolt and each shear face in multiple shear face connections
Appendix B (Informative Appendix) Values divided by
Appendix C (normative appendix) design weld stresses owsd and wsd
Appendix D (normative appendix) slope constant m values and characteristic fatigue strength No. AT
Calculated values of the extreme design stress range Aord and Aord
Appendix E (normative appendix)
Appendix F (informative appendix) Estimation of stress-squared cycles - example
Appendix G (informative appendix) Calculation of joint stiffness under tensile loading
Bibliography

Foreword
1 Scope
2 normative reference documents
3 terms, definitions, symbols and abbreviations
4 Overview
5 Static strength verification
6 Fatigue Strength Verification
7 Sexual stability verification
Appendix A (informative appendix) Ultimate design shear for each bolt and each shear face in multiple shear face connections
Appendix B (Informative Appendix) Values divided by
Appendix C (normative appendix) design weld stresses owsd and wsd
Appendix D (normative appendix) slope constant m values and characteristic fatigue strength No. AT
Calculated values of the extreme design stress range Aord and Aord
Appendix E (normative appendix)
Appendix F (informative appendix) Estimation of stress-squared cycles - example
Appendix G (informative appendix) Calculation of joint stiffness under tensile loading
Bibliography