Investigation of stress distribution in upholstery of soft furniture

In the process of use, upholstery of soft furniture undergoes continuous deformation. This results in puckering of upholstery, change of its initial shape, whereas longer usage of upholstery leads to deterioration thereof. For investigation, an original testing bench of soft furniture has been applied. After inducing transverse resonant oscillations in soft pieces of furniture, stress in upholstery of soft pieces of furniture and stress distribution over the plane have been assessed. Variation of the value of the load simulating the tensioning defect of upholstery allows determining an adequate change in stress of upholstery. Under the action of the load, the following uneven changes in stresses have been established irrespective of the initial condition of stresses in soft pieces: some places demonstrate decrease of stresses, whereas other ones show increase thereof up to a few times. It has been illustrated that variation of the position of the additional load in respect of the investigation point leads to ‘accentuation’ of stresses in the close area. The methodology and equipment presented may be employed to assess the assembling quality of soft furniture in the process of manufacture and use.