Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

Search results for query: *

  1. jedstress

    help on using BS13155:2020 for design a simple lift beam

    Hi desertfox, I can confirm that the lifter will operate <16000 cycles. I recall reading that extract but what confused me was "only need to consider the global safety of the proof of static strength". The author from the link ignored all partial safety factors etc for <16000 cycles for static...
  2. jedstress

    help on using BS13155:2020 for design a simple lift beam

    Desertfox, I have read BS13155 and it seems to cover various types of lifters includimg lifting beams, clamps, C hooks etc. And it has also been specified by the client. Therefore, I'm confident that it applies to the main lifter fabrication too. Rb1957, I wasn't sure what you meant by your...
  3. jedstress

    help on using BS13155:2020 for design a simple lift beam

    The lifting beam shall be designed for a maximum of 16 000 load cycles. Going off the below link, it seems as though, for <16000 load cycles, the requirement is basically 2x load for elastic and 3x load for ultimate. The resulting stresses are then compared against the material allowable. All...
  4. jedstress

    pretorque required for a friction joint (shear load) when exposed to temperature change

    Desertfox, many thanks for clarifying the thermal bolt load query. You have definitely helped me better understand the task within a very short space of time. So thanks once again for putting up with me :). Yes I would appreciate it if you could look into my other thread too.
  5. jedstress

    pretorque required for a friction joint (shear load) when exposed to temperature change

    Hi Desertfox, Slightly off-topic question, have you ever used BS13155:2020 for the assessment of lifting beams? I've added a separate post regarding this British Standard and was wondering if you had ever implemented it. Hopefully I will get some replies on that thread soon. You have been...
  6. jedstress

    pretorque required for a friction joint (shear load) when exposed to temperature change

    Hi desertfox, Thanks for the link. For my own knowledge, wouldn't The bolt area and flange local area have an impact on the thermal induced bolt stress i.e. the stiffness of the various parts? The link uses only deltaT, thermal coefficient difference and bolts youngs modulus to calculate the...
  7. jedstress

    help on using BS13155:2020 for design a simple lift beam

    Hi all, I am currently working on a lifting beam which has to be designed/analysed in accordance with BS13155:2020. In the past, I have designed lifting beams which were based upon the clients own safety factor requirements and manuals, therefore BS13155 wasnt used as such. The following is...
  8. jedstress

    pretorque required for a friction joint (shear load) when exposed to temperature change

    Hi desertfox, Thanks for the response. The two flanges forming the bolt joint will be made from some carbon steel (one will be S355, other is unknown right now but a carbon steel). The bolts will most likely be grade S. So the coefficient of thermal expansion amongst the bolted joint hopefully...
  9. jedstress

    pretorque required for a friction joint (shear load) when exposed to temperature change

    Hi all, I am currently working on a problem which involves exposing a bolted joint to an increase in temperature (delta 250 C). In the past I have dealt with typical pretorqued bolt joints (ambient temperature) where the required pretorque was approximated by working out the actual required...
  10. jedstress

    Contact body analysis sol101

    Hi Karachun, Thanks for the feedback. I can't use enforced displacement because the displacement is unknown. And you mentioned constraining the degrees of freedoms except for the load direction. Wouldn't that still give rigid body motion in the load direction? Typically that's the case in...
  11. jedstress

    Contact body analysis sol101

    Hello, I would appreciate it if someone could give me advice regarding constraint requirements in sol101 contact body analysis. So I have a rectangular plate clamped around its edges. An unconstrained cylinder is pushing down on it using a force card. Contact bodies have been defined. Is that...
  12. jedstress

    loads due to applying torque to the nut of a threaded bar in the middle of a simply supported beam

    Hi desertfox. The item is used occasionally and thus fatigue should not be of concern. Hi rb1957. The clamp up load has been inherited from the original design and only minor mods have been made to the design. Thus the load is a carry over from the original spec. It has been questioned but...
  13. jedstress

    loads due to applying torque to the nut of a threaded bar in the middle of a simply supported beam

    Hotrod10 Thanks alot for the clarification. The previous report that I inherited had not accounted for this preload and had only stressed it to the applied hydraulic load despite the preload being far greater. And I couldn't even find any requirement for the pretorque yet the instruction manual...
  14. jedstress

    loads due to applying torque to the nut of a threaded bar in the middle of a simply supported beam

    Hotrod10, the preload is applied on the casing of the hydraulic cylinder. Thus the pressure gauge will show zero pressure in the presence of only the preload due to the recessed design of the piston and load transfer via surface abutment. Hope that answers your question.
  15. jedstress

    loads due to applying torque to the nut of a threaded bar in the middle of a simply supported beam

    canpro, it seems like the more I look into it the more confused I get. However, based upon my interpretation of hotrod10s explanation, would you agree with my last post?
  16. jedstress

    loads due to applying torque to the nut of a threaded bar in the middle of a simply supported beam

    Thank you everyone for the responses I have received so far. HotRod10, after drawing the following sketch of my setup, I can make sense of what you were talking about earlier. The hydraulic block region essentially behaves like a clamped joint where the 10kN preload due to the 50Nm torque needs...
  17. jedstress

    loads due to applying torque to the nut of a threaded bar in the middle of a simply supported beam

    Hotrod10,I will try to use an example to better explain what I think is happening and by all means correct me where you disagree please. Torque applied = 50Nm = assumed 20kN. Reaction at each beam end (hydraulic interface) = 10kN. External hydraulic force applied at each end = 9kN. Therefore...
  18. jedstress

    loads due to applying torque to the nut of a threaded bar in the middle of a simply supported beam

    Hi HotRod10, Just a clarification that the 50Nm torque is not actually the required force but it has been stated in the instruction manual as part of setting up the assembly. So I guess it just seats the beam. The actual applied load is via the hydraulic interface which in turn pushes down on a...
  19. jedstress

    loads due to applying torque to the nut of a threaded bar in the middle of a simply supported beam

    hi canpro, I am not 100% sure if I follow you when you say 'But try to picture what is happening physically'. From your recent post it seems like you agree with me adding the pretorque load and the external applied load to get the total load in the system. Correct?
  20. jedstress

    loads due to applying torque to the nut of a threaded bar in the middle of a simply supported beam

    rb1957, would you use the typical preload equation of T=F*K*D to evaluate the preload? I wasn't so sure because it isn't your typical joint where the mating surfaces are in compression. If I was to use the above equation for an M12 coarse thread bar, I get a preload value of approximately 21kN...
Back
Top