25 Jan AN AMERICAN NATIONAL STANDARD. ASME BTH-1– (Revision of ASME BTH-1–). Design of. Below-the-Hook. Lifting Devices. Buy ASME BTH 1: DESIGN OF BELOW-THE-HOOK LIFTING DEVICES from SAI Global. ASME BTH Design of Below the Hook Lifting Devices Reduced – Download as PDF File .pdf), Text File .txt) or read online.
|Published (Last):||26 November 2014|
|PDF File Size:||2.44 Mb|
|ePub File Size:||10.61 Mb|
|Price:||Free* [*Free Regsitration Required]|
ASME BTH – Structural engineering other technical topics – Eng-Tips
If the length of a bolted connection exceeds about 15 in. The horsepower selection shall be specified by a qualified person giving full consideration to the frictional losses of the lifter, the maximum locked rotor torque required, and the geometry of the speed torque curve of the motor applied.
In reality, actual use of the lifter may differ, possibly significantly, from the defined load spectra. The Committee selected the upper temperature limit as a reasonable maximum temperature of operation in a summer desert environment.
The minimum center-to-center spacing of plug welds shall be four times the diameter of the hole. This section identifies requirements of fluid power systems and components for below-the-hook lifting devices. Equations through are based on the behavior of beams that are restrained against twist or lateral displacement at the ends of the unbraced length, Lb.
The design criteria set forth are minimum requirements that may be increased at the discretion of the lifting device manufacturer or a qualified person.
Cite the applicable edition of the Standard for which the interpretation is being requested. The term VS is the coefficient of variation of the spectrum of loads to which the lifter may be subjected. Design Category A lifters are considered to be used at relatively high percentages of their rated loads.
However, members of the construction community expressed the need for design criteria more suitable to their operating conditions, including a lower design factor, and the necessity to address other failure modes such as fracture, shear and buckling, and design topics such as impact and fasteners. Welding procedures for other metals are to be established by a qualified person.
ASME-BTH – Free Download PDF
A slip-critical connection is a connection 2101 transmits shear load by means of the friction between the connected parts. Resources Few production environments have the luxury of ordering new equipment to replace existing machines on their shop floor.
For circular amse with compact walls as defined by Table As a consequence, industry has for quite some time expressed a need for a comprehensive design standard for below-the-hook lifting devices 2011 would complement the safety requirements of ASME B Plug and slot welds may be used to transmit shear in lap joints or to prevent buckling of lapped asmme and to join component parts of built up members. A lower allowable bearing stress may be required between parts that will move relative to one another under load.
Classical design aids such as Table 9. Thus, the use of Design Category A is restricted to lifting device applications with low numbers of load cycles Service Class 0. In lap joints, the minimum amount of lap shall be five times the thickness of the thinner part joined, but not less than 1 in.
No standards have been 22011 for design factors of pneumatic components. Fillet weld size is specified by leg width, but stress is determined by effective throat thickness. The inclusion of lateral forces in this paragraph is intended to refer to calculated lateral forces that occur as a result of the intended or expected use of the lifter.
Intermittent groove welds are not permitted. The Service Class establishes allowable stress range values for lifter structural members and design parameters for mechanical components. In addition, lifters such as bar tongs and vertical axis coil vth have other special load handling conditions e.
As is the practice in bbth above-cited standards, the design factor with respect to buckling in the inelastic range [eq. The allowable tensile strength through the pinhole, Pt, shall be calculated as follows: These are tension asmee the effective area on a plane through the center of the pinhole perpendicular to the line of action of the applied load, fracture on a single plane beyond the pinhole parallel to the line of action of the applied load, shear on two planes beyond the pinhole parallel to the line of action of the applied load, and by out of plane buckling, commonly called dishing.
The SI units in the 20111 have been directly softly converted from U. Tests on overhead cranes Madsen, showed somewhat less severe dynamic loading.
Compression elements that are more slender than are permitted for noncompact shapes may fail by local buckling at stress levels below the yield stress. The configuration of bolted connections in lifting devices will likely vary greatly from the standard types of connections used in steel construction. As with slender plates subjected to shear, below-thehook lifting devices are not generally composed of slender compression elements. With tighter production processes, closer metallurgical control, and better quality checks in current practice, the risk of such failure is reduced.
For channels bent about the major axis, the allowable compressive stress is given by eq. Along with these technical changes, the nonmandatory Commentary for each chapter was moved to its own respective Nonmandatory Appendix. In the absence of similar research results using other types and grades of bolts, para.
If the exposure is prolonged and cyclic in nature, the creep rupture strength of the material, which is lower than the simple elevated temperature value, must be used in determining the design rated load and life of the device. The allowable shear stress expression is based on CMAA 70, which specifies the allowable shear stress as a function of the shear yield stress. Thus, the peak bending stresses due to curvature must be evaluated for members subject to cyclic loading and for which the fatigue life must be assessed, but need not be considered for static strength design for members in which the plastic moment can be attained.
The BTH Committee developed a set of static and dynamic load spectra based on the judgment and experience of the Committee members.